Felipe Massa has announced that this season will be his last in Formula One.

The Brazilian Williams driver is out of contract at the end of the year.

Massa's best season came with Ferrari in 2008 when he finished as runner-up in the drivers' championship to Britain's Lewis Hamilton.

Despite winning the final race of the season that year in his home country of Brazil, Hamilton pipped him to the title by just one point in a dramatic last lap that secured fifth place and the championship.

Massa survived a near-fatal head injury after crashing in qualifying for the Hungarian Grand Prix in 2009.

The incident occurred when a suspension spring that had fallen off another car on track struck his helmet. 

He had a titanium plate inserted into his skull after surgery around his left eye after the accident.

During his career, Massa also raced for Sauber in his first three seasons.