Internet search engine Google has posted record quarterly profits on the back of strong advertising sales.

Google recorded a net profit of $381.2m for the third quarter, compared to $52m for the same period a year ago.

Revenue rose to $1.578bn, up by 96 per cent on the same quarter last year.

The US-based company attributes the rise in its quarterly profits to an increase in its online search advertising.

Founded by internet entrepreneurs Sergey Brin and Larry Page in California, the company receives money from advertisers each time an internet user clicks on adverts displayed next to its search results.

"Although this is typically a slower season for Internet properties, we had another exceptional quarter," said Google chief executive Eric Schmidt.

"Our focus on end users and on quality of information and advertising worldwide continues to work extremely well. We are very pleased with how well this is working at scale."

Shares in the firm closed down almost 2 per cent at $332.46 ahead of the announcement of its results.

This week US rival Yahoo also revealed a six-fold increase in net profit to $254m.