The Prime Minister has pledged to support manufacturing as he congratulated a company which is taking on 350 workers after winning two massive contracts.

David Cameron visited Burntisland Fabrication (BiFab) in Fife just after bosses there announced new contracts worth £140 million involving the design, procurement and construction of major components for a new oil platform.

He told workers at the firm that, in the past, Britain's economy was "too reliant on financial services and banking".

Mr Cameron stressed the importance of "high-quality manufacturing" and said that the Government will "try and do our bit" to help manufacturing.

The new work at BiFab, for Premier Oil's Solan development near Shetland, means the workforce will have doubled in size by December. It also allows the firm to continue the apprenticeship programme it began five years ago.

The contracts are expected to be completed by April 2014 and will involve BiFab's sites in Methil and Burntisland in Fife and Arnish on Lewis.

Mr Cameron met bosses and apprentices as he toured BiFab's site in Buckhaven in Fife, a visit he described as a "good intermission" between taking the French president to the Olympic handball and taking the Russian president to watch judo at the Games on Thursday.

BiFab works with the oil and gas sector and the renewable energy sector. The Prime Minister hailed the company as a "great British business that is doing fantastic things".

He said: "Our economy had become far too reliant on financial services and banking, rather than actually making things. And here what you're going to be doing over these coming years, if everything goes well in the oil sector and the renewables sector, is really important, high-quality manufacturing, and I think that's something to celebrate and something to stand up for.

"It is absolutely vital we have got diverse supplies of energy, that we fully exploit the North Sea and the oil and gas that is available but also we make the most of the renewable energies of the future, and you're doing both those things right here at BiFab."

The company was praised for providing "good, well-paid jobs for people who live in this area and also for future generations", describing the plan to take on 15 apprentices a year for the coming years as "really impressive".

He added: "I can commit that we will try and do our bit to help, whether that's helping with the oil offshore allowances we put in the last budget; whether its supporting apprenticeships, I think there were 450,000 apprentices started last year which was a record year; or anything else we can do to encourage manufacturing and local content as you're demonstrating here.

"So from me as Prime Minister just a very big congratulations to BiFab, to Premier Oil, but above all to the workforce here who have made this possible. It's great news that you're going to be building this stuff here in Scotland rather than having it imported from elsewhere."

Scottish Secretary Michael Moore was with the Prime Minister on the visit.

He said it is "fantastic to see a very successful manufacturing company and to see the energy sector continuing to provide so many prospects for jobs".

BiFab won a contract with Premier Oil to provide a 3,500-tonne topsides module (the part of an oil platform which sits above the water and houses the oil production plant), an accommodation block and drilling rig.

The other contract is for an 8,000-tonne jacket (an oil platform's underwater support structure).

Mr Moore said the waters the platform would eventually sit in, to the west of Shetland, are "some of the most challenging environments for oil and gas production" and that it is a "great tribute to BiFab" that it won the contracts.

The new contracts will underpin the company's work with apprentices, he said.

"As I understand it, their aim is always to have 50 apprentices on the books at any given time. That requires a good flow of work and these huge contracts are very good news for that.

"Oil and gas will continue to have a huge part in the UK's economy for decades to come. This latest extension of work in Shetland underlines that.

"But even in traditional areas of the North Sea, there is still substantial potential, and companies like BiFab are very well-placed to be part of that."

BiFab managing director John Robertson said: "The two contracts were won, we believe, not only due to a commercially attractive bid but also due to the ability and experience of BiFab's management and workforce to deliver a quality product, on schedule and with a good safety culture.

"This latest success enhances BiFab's growing reputation as a major manufacturer of topsides and jackets for the North Sea. BiFab is known as one of the largest manufacturers of jacket sub-structures for offshore wind turbines, but this is the largest jacket to date for the oil and gas sector.

"Recognising the future demands for a highly skilled workforce, BiFab introduced an apprenticeship training scheme in 2007 with the aim to have a rolling programme of 50 apprentices in the scheme at any one time. The award of this project will allow us to continue this programme."

Premier's regional manager for the North Sea, Nigel Wilson, said: "We are delighted to have awarded the contracts for the jacket and topsides, which constitute the largest components of the Solan field development, to BiFab."