A small Norwegian company is planning a stock market listing as part of its plans to go head to head with Microsoft.

Oslo-based Opera Software is expected to be floated with a market capitalisation of about $140m (£75.3m), which compares with mighty Microsoft's near $300bn valuation.

But the competition in the market for internet browsers that can be used with mobile phones is not as uneven as it looks, according to Opera's chief executive, Jon von Tetzchner.

Microsoft dominates the global market for desktop browsers but Mr Von Tetzchner reckons that "in the new markets, like mobile, Microsoft is not as significant a player at this moment". He says that Opera's ability to use the same core internet browser technology for mobile phones as for desktop computers gives it an edge over its rivals, including Microsoft.

Mr Von Tetzchner and a colleague, Geir Ivarsoy, set up Opera in the mid-90s and their original two-man band has now grown to a company that employs about 140 people. The flotation is expected to raise between $10m and $20m.

The two men, who each own more than 20% of the company, resisted the temptation to cash in on the dotcom boom because the company was not then ready for a stock market flotation. They say they do not regret the decision.

"If we had gone public then we would have followed the market down. We would much rather be on an upward trend," Mr Von Tetzchner said.