Shares in Google moved past the $600-a-share mark for the first time on Monday extending a rally that has lifted the internet search and advertising giant's market value by about $25bn in just the past month.

Although the shares fluctuated around $600 during the morning in New York, their performance will serve as another reminder of the enormous wealth created by the nine-year-old Mountain View, California-based company since it went public at $85-a-share in August 2004.

Based on its current share price, Google has a market value of $187bn - more than many bigger, more mature businesses such as Wal-Mart, Coca-Cola, Hewlett-Packard and IBM.

Read more: msnbc.msn.com