Scottish Enterprise is providing a further £1.5 million to support the company's new Process Engineering Centre in Renfrew, western Scotland.
The development will create 266 jobs in Renfrew and 114 at other sites in the UK and overseas, including engineers and project managers.
Andy Hunt, chief executive of Doosan Babcock, said: "The opening of this centre is fantastic news for Scotland and for Doosan Babcock as we seek to grow our process business, creating new roles for British engineers.
"The process sector can be a highly complex area to operate in but, thanks to this investment, Doosan Babcock will have the skill set and specialist knowledge to offer customers an integrated engineering and construction service that is unparalleled."
Lena Wilson, chief executive of Scottish Enterprise, said: "Doosan has ambitious plans for expanding its process business on the world stage and it is testament to our key capabilities and skills that Scotland has been selected as the location for such a pivotal part of the company's global growth plans.
"The company's decision to locate this new service here is an excellent example of how the support that we and our partners can offer is helping bring new investment into Scotland. We know that is well recognised internationally, with foreign direct investment into Scotland currently at its highest level for 15 years."