THE son of two high school drop-outs, Ralph Alexander had a very simple-sounding ambition when he was growing up in 1960s New York. ''I was the first person in my family to go to college and I wanted to be successful, whatever that meant,'' says Alexander, who has been achieving in spades ever since.

In fact, they don't come much more successful than the BP veteran, who these days lives in Surrey and is one of the main board directors reckoned to be in contention to succeed Lord Browne as head of Britain's biggest company.

Passing through Edinburgh en route to BP's Grangemouth refining and chemicals plant earlier this week, however, Alexander was looking forward to achieving an ambition that he set more recently, although it will see him leaving the colossus soon.

''I am 50 next year and I swore on my 49th birthday that by the time I turned 50 I would have changed my life considerably. It was time to go back to the States and it was time to run my own company,'' recalls the Brooklyn Polytechnic graduate who is chief executive of the $9bn refining and petrochemicals operation that will spin out of BP next year.

As the head of the olefins and derivatives business, which owns two refineries and a series of plants producing chemicals like polyethylene, Alexander will be running what will be one of the world's biggest companies from the day it becomes a separate entity next April. The company will float in the second half, but BP expects to retain a holding in it until late in 2007.

To be headquartered in Chicago, Illinois, the firm is being groomed for the New York Stock Exchange to be sure of commanding attention from a big enough investor base.

Nonetheless, thanks to the fact the Grangemouth refining and petrochemicals production facility has been included in the yet-to-be-named venture's birthright, its fortunes will be studied especially closely in Scotland.

Following hundreds of job losses at the plant in recent years, some observers were left feeling that BP's agenda was probably to close it, in an age when the world's attention was moving eastwards.

Alexander, who says he will approach the new job equipped with the equivalent of a PhD in management after working closely with the masterful Browne for years, is frank about the disadvantages of having a plant on the banks of the Forth.

''It's in a location that you would not necessarily build in today. It's far removed from Middle Eastern resources, it's not particularly close to markets. I mean, Europe's the slowest-growing market on the planet.''

But chatting easily in a voice that comes straight out of NYPD Blue, he is withering about the sceptics while enthusiastically outlining his vision of a potentially prosperous future for Grangemouth.

''BP's agenda has never been to close Grangemouth. I've been in BP over 20 years and been on the executive committee for the last three and there's no strategy that's aimed at Grangemouth.''

The giant facility is being transferred to the new company chiefly because the refining and chemical production operations there, like those at a similar plant at Lavera in France, were felt to be so closely integrated that trying to separate the two would not be viable.

Noting that $1.3bn ((pounds) 680m) has been invested in improving Grangemouth since 1998, Alexander says the plant will mean a huge amount to him.

''This [Grangemouth] is 20% of my company. I have been here three times in the last month and this is going to work, period. There's no reason Grangemouth should not be a viable, productive piece of this company. It has to be and it will be.''

His confidence is based partly on the belief that the ''newco'' will benefit from having a ''much lighter management'' framework allowing scope for greater local initiative than may have been the case under BP.

While returns at the unit have averaged around half of those seen in sexier parts of the empire like upstream exploration and production, by working the assets harder, marketing an expanded product range aggressively and boosting margins, the company can grow returns significantly.

At Grangemouth, this could mean developing products and recruiting customers while possibly sourcing feedstock from a wider range of locations.

Alexander also wants to get the refining and chemicals operations working together as one business rather than two that happen to be neighbours, to ensure cross-fertilisation of ideas and to maximise efficiency.

In view of the hard work BP has already done on cutting costs, he does not expect employee numbers to change materially at the operations, which currently employ around 1300 staff, including contractors.

Some managerial posts may no longer be necessary, but those affected will probably be absorbed elsewhere within BP, which has said there will be no compulsory redundancies associated with the transfer of the plant.

However, sports fanatic Alexander is also clear that Grangemouth's survival will depend on management's ability to hone performance and to outplay rivals such as Dow and BASF.

Other plants within his empire will also be seeking resources from head office, which has sanctioned (pounds) 1.4bn investment in a 50% stake of a new facility in booming Shanghai, China, that Alexander describes as ''quite unique''.

''We're aiming to have one manufacturing site at Grangemouth that's the best in the world and that's what it will have to be if its going to be successful.''

In coming months, Alexander and his team will consider plans to invest in developing facilities to import crude oil from new sources and export more products.

In view of the importance of Grangemouth, which has been estimated to account for around 8% of Scottish GDP, he is looking forward to detailed discussions with the Scottish Executive and others about how they might help.

''This means a conversation with the broader constituency including your wonderful universities. I know the executive is keen to see business flourish here and I expect we'll get support in thinking this through.''

Alexander, who met Scottish Enterprise head Jack Perry this week, emphasises the importance of high quality people to Grangemouth in fields like engineering.

The newco is not looking for direct financial support from the executive but Alexander admits the decision to locate the new group headquarters in Chicago - where Amoco was based before BP acquired it - followed generous support from the Windy City's authorities.

''It's an economy where government and business seem to work in a way that I've never seen before. The mayor is deeply interested in what we're doing in Shanghai and he wants to participate in helping us to be successful. I'm sure we'll see the same thing here in Scotland but that remains to be seen.''

Politicians will soon know of any official moves, such as new environmental regulations, that the company considers to be unhelpful, and what the consequences might be for its Scottish operations.

As a longstanding fan of Scotland, though, Alexander is not averse to the idea of spending more time in the country if that is what promoting the interests of his biggest asset require.

By the sound of it Shirley, the high-school sweetheart to whom he has been married for 27 years, will probably not object either.

''My wife's very familiar with the quality of goods here. I went to New York recently and everything I wore was from Scotland where she'd just gone shopping.''

Besides educating Scottish politicians, Alexander is happy to pass on a lesson for fathers of teenage girls across the world that he has learned recently, while watching romance blossom between his 19-year-old daughter, Brooke, and her Finnish

boyfriend.

''No father likes boyfriends but if you've got to have a boyfriend Finland's not bad because they have compulsory military duty. So she went off to college as he went into the military. It was perfect.''

BOY FROM THE BOROUGHS

BORN: Queens, New York City, 1955.

EDUCATION: Obtained a Bachelor's and Master's Degree in nuclear engineering from Brooklyn Polytechnic. Went on to get a Master's Degree in management from Stanford University, where he spent a year as a Sloan Fellow in 1991.

EMPLOYMENT: Started in oil and gas with Exxon in Houston, Texas, in 1977. Since joining BP 22 years ago has had increasingly high-powered roles in upstream, downstream and finance including: vice president, Gulf of Mexico; head of Upstream M&A; head of group strategy/group controller; group vice-president, downstream, responsible for new markets development; and executive vice-president and chief executive for gas, power and renewables. Joined petrochemicals as chief executive July 1, 2004. Has been a member of the group chief executive's committee for three years.

LIVES: Oxshot, Surrey, with wife of 27 years Shirley. Their 19-year-old daughter, Brooke, is a student at Auburn University near Atlanta, Georgia.

INTERESTS: Sports, including playing basketball and golf, music, theatre and books. Favourite authors range from Tom 'Hunt for Red October' Clancy to former US president Thomas Jefferson.

AMBITIONS: To build something really extraordinary, to take something like this company which starts in a decent place but not the best place and trying to develop a company that's really great measured by many different characteristics by shareholders and the communities we are in.

ON the unexpected satisfactions of life in the oil and gas industry: ''I've had a wonderful career. It opened up doors for me that I never could have imagined. I've travelled all over the world, the technology is interesting and the people are extraordinary. I would never have guessed that when I graduated. I thought oil and gas, that's boring.''

ON working with Lord Browne: ''He's smart, hard working and he loves the company. The thing that amazes me about John is how he can keep such a high level of thinking for so long. He thinks, he makes considered judgments and he acts; he doesn't over-analyse.''