Three of the top 20 Microsoft Corp investors had been lobbying the board to push for the computer software maker's founding chairman Bill Gates to step down from his post, according to sources familiar with the matter. Microsoft Corp was established by Gates 38 years ago.

The company's former chief executive officer Steve Ballmer had been under pressure from investors for years to improve the performance of the software maker. However, this was the first time that major shareholders in the company had aimed at Gates, who is one of the most influential and respected figures in the technology industry.

On Tuesday, a representative for Microsoft declined to give statements regarding the report.

The board of Microsoft did not show signs that it would heed the wishes of the three investors, said sources. The said three investors collectively hold more than 5% of Microsoft's stock. The sources asked the identity of the investors to be kept anonymous as the discussions were held private in nature.

The said top investors had been urging the Microsoft's board to push Gates to step down as they were concerned regarding his role as chairman of the company. The investors said that Gate's chairmanship would block adoption of new strategies and would limit the power of a new CEO to make substantial changes. Particularly, the investors had pointed to Bill Gates' role in the special committee established to search for Ballmer's successor.

Gates holds around 4.5% of the USD277 billion firm and is the largest individual shareholder at Microsoft.