M2 Subsea - headquartered in Westhill - will tackle explosive devices lying at the bottom of the Baltic Sea since World War 2.
Two remotely-operated vehicles (ROVs) will work from the Go Electra support vessel.
The contract was awarded by Next Geosolutions.
M2 Subsea chief executive officer Mike Arnold said: "This contract award from Next Geosolutions is great for the business and a significant scope of work for us to win.
"It highlights both our capabilities to negotiate what is a very challenging subsea environment.
"Safety is a key factor on every project and in particular where it involves surveying the seabed to identify undiscovered explosive devices for removal."
An Aberdeenshire subsea business has won a contract worth more than £1m to remove explosives from around the world's longest pipeline.