Norwegian floating production storage and offloading vessels company BW Offshore has stamped a deal to buy an additional 30 percent in Maromba field offshore Brazil from U.S. oil firm Chevron.

The acquisition is subject to fulfilment or waiver of conditions precedents, including approval by Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP).

Under the pact, BW Offshore will pay $25 million for the stake in Maromba over three milestones with the first of $10 million after approval of ANP.

The second milestone of $5 million is due at the start of drilling activities and the third part-payment, representing the other 10 million, after achieving cumulative production of 250,000 barrels of oil from the area.