Renfrew-based Doosan Babcock will also be handed a further £1.5 million by Scottish Enterprise to support its new Process Engineering Centre.
The development will create 266 jobs at its headquarters and 114 at other sites in the UK and overseas.
The Korean-owned company already has more than 4,000 employees in the UK in nuclear, oil and gas, petrochemical and thermal power generation sectors.
Doosan Babcock chief executive Andy Hunt said: "The process sector can be a highly complex area to operate in but, thanks to this investment, we will have the skill set and specialist knowledge to offer customers an integrated engineering and construction service that is unparalleled."
Finance Secretary John Swinney said it was a "sign of confidence in Scotland as a great place to do business and a great place to invest".
However, the announcement comes just as oil giant Chevron has said it will cut 225 jobs in Aberdeen as it reorganises its North Sea operations.
The US firm said employees, contractors and expatriate workers would be affected.
The company said: "Chevron Upstream Europe (Cue) is reorganising its business unit in Aberdeen. Cue has previously conducted periodic organisational reviews to ensure alignment with its portfolio and provide the flexibility to allow the company to leverage other growth opportunities in the North Sea."
As both companies made their announcements, it was revealed employment in Scotland has reached its highest ever figure despite an increase in the jobless total.
The number of people in work rose for the 17th consecutive month to stand at 2,587,000 for the period March to May, with 76,000 more in employment than at this time last year. But at the same time, unemployment - which includes those who are out of work and not eligible for benefits - rose by 13,000 from the previous quarter to 192,000.
Scotland's unemployment rate is now higher than that for the UK as a whole, at 6.9 per cent north of the Border compared to 6.5 per cent for the UK. However, the employment rate in Scotland is 73.3 per cent, which is better than the UK rate of 73.1 per cent.
The proportion of women in work is also higher north of the Border, and the number of Scots who are out of work and claiming Jobseeker's Allowance fell 4,000 from the previous month.
Scottish Secretary Alistair Carmichael said Scotland had seen "positive developments" but there was still a need for "the right conditions to get people into jobs".
Labour claimed women were bearing the brunt of the rise in the jobless total - female unemployment grew by about 11,000 over the quarter - and urged the Scottish Government to do more. Deputy finance spokeswoman Jenny Marra said: "While we welcome the increase in employment, the SNP can't hide behind population growth and they need to face up to the decisions they are making which result in more women being out of work."
Meanwhile, Scottish Trades Union Congress general secretary Grahame Smith called on both the UK and Scottish Governments to "rethink their increasingly complacent views on the state of the Scottish labour market".
He said unemployment was "stubbornly high" at three percentage points above its pre-recession level, and added: "While it may be technically true to argue that the employment level in Scotland is at a 'record high', the employment rate is still well below its peak of 2008."