Mainstay Marine Solutions will complete the first stage of an energy converter project for wave technology company Wave-Tricity.
Wave-Tricity secured £4m in EU funding in September to develop and test a new device called the Ocean Wave Rower.
It will be trialled in a wave energy site off the south Pembrokeshire coast for two years from February 2017.
Mainstay, which build boats and marine energy devices, employs 80 people.
Managing director Stewart Graves said: "We are looking forward to working closely with Wave-Tricity on this pioneering scheme."
A Pembroke Dock company has won a contract to build a new device for a £5.8m wave energy scheme.