Facebook CEO Mark Zuckerberg has denied rumours that the company is planning to release its own smartphone.

Zuckerberg was quoted by the BBC as saying that releasing a Facebook phone was not the right strategy. "We need to make Facebook really good across all of the devices [that people use]," he said.

For the fourth quarter of 2012, the company posted a net income of $64m, a significant decline from the £302m it reported in the same quarter the year before.

Mobile Facebook users have exceeded desktop users for the first time in Q4 2012 and by December 31 2012 the social network had 680 million monthly active users, an increase of 57% year-over-year.

The company said that mobile revenue represented nearly a quarter of all advertising revenue for the fourth quarter, up from 14% of advertising revenue in the previous quarter.