WPP, the world's largest advertising company, recovered from third quarter weakness to post annual growth of 2.9% in organic revenue, ahead of expectations.

WPP's portfolio includes Ogilvy & Mather and Young & Rubicam and its clients include Microsoft, Procter & Gamble and Shell.

It said headline operating margins rose 0.5 points to 14.8%, in line with expectations.

A strong end to the year echoed performances from rivals Omnicom and Publicis, who cited an improvement in emerging markets and the US and were cautiously optimistic on the outlook for 2013.