Google's search engine is sailing through its first recession as a public company.

The company last night beat analysts' expectations for fourth-quarter profit and grew advertising revenue by 22%.

It benefited from advertisers turning to the internet to promote products over the Christmas shopping period.

Net profit was $382.4 million (£278.3 million). That was down 68% from the same period the year and included a $1.09 billion writedown on investments in AOL and Clearwire Corp - a builder of high-speed internet services.

Overall spending in the US on ads linked to web-search results rose 21% last year, down from growth rates of 30% in 2007.

Revenue from Google's own sites increased 22% to $3.81 billion, accounting for about two-thirds of overall sales, the company said. Ad sales from Google's partner sites rose 3.5% to $1.69 billion.

As Google was unveiling its results, rival Yahoo announced a freeze on annual pay rises as it tries to cope with slowing online advertising.

Yahoo stock has fallen 43% in the past year.