ZURICH (Reuters) - Europe's biggest biotech expects it new heart and lung drug Opsumit to be on sale in the United States this year if it receives approval from regulators in October.

"The assumption is that we will be on the market with macitentan (Opsumit) in the U.S. this year," Chief Financial Officer Andrew Oakley told Reuters in an interview.

Actelion is banking on Opsumit, also known as macitentan, to reduce its dependency on its main product Tracleer, which goes off patent in 2015 and is also facing competition in the U.S. from Gilead's Letairis.

U.S. health regulators are expected to make a decision in October.

Spokesman Roland Haefeli declined to comment on the pricing of Opsumit, saying details would be announced when the drug is launched.

Actelion posted full-year net profit of 303 million Swiss francs ($330 million), in line with a forecast for 303 in a Reuters poll, and said it would hike its dividend by 25 percent.

(Reporting by Caroline Copley)