The latest phase of Google’s dizzying stock market ascent saw its shares rise above $400 for the first time on Thursday, valuing the company at nearly as much as rivals eBay and Yahoo combined.

At $112bn, the internet search engine company’s stock market value has also edged past that of Cisco Systems, the maker of internet equipment that enjoyed a brief moment as the world’s most valuable company at the height of the first internet boom.

Google’s stock has risen about $100 since it dazzled Wall Street with unexpectedly strong third-quarter earnings a month ago. Since then, analysts’ average estimate of next year’s earnings has been raised $1.12 to $8.44, according to IBES, which monitors analysts’ predictions. While earnings estimates have risen about 17 per cent, the shares have jumped more than twice as fast.

Despite a rapid ascent that echoes the euphoria of the dotcom boom, most analysts continue to be strong supporters of the stock, expecting it to rise further. Of 34 analysts who have ratings on Google, 25 recommend that investors buy the shares and eight rate it a “hold”, according to data from Bloomberg.