Norskan Offshore, a subsidiary of DOF, has secured four charter contracts worth Nkr5.2bn ($38m) from Petrobras.
The eight-year agreement involves four large anchor-handling tug and supply vessels, Norskan said.
The company will use two newbuilds under construction at the STX Promar shipyard in Brazil, which is owned by STX Europe.
Norskan is negotiating with STX Promar for another two newbuilds to meet the agreement.
The charter contract is expected to commence in 2011-13.