Internet search engine Google says earnings have quadrupled after announcing its quarterly results.

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

Google recorded a net profit of $342.8m for the second quarter, compared to $79.1m for the same period a year ago. This week US rival Yahoo also revealed a six-fold increase in profit to $754.7m.

Boosted by strong revenue from advertising, shares in Google, which is valued at about $86bn (£49bn), reached $313.94 on Thursday - a record high at the close of the Nasdaq.

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.

Revenue from the above search advertising rose to $1.38bn, compared with $700.2m in the same period last year.

"We had an excellent quarter. We continued to innovate, we continued to execute and we stayed focused on our users," said Eric Schmidt, Google chief executive officer. "Google had another solid performance."