Shareholders of Microsoft Corp had been given advice by Proxy advisory firm Glass Lewis to vote against board director John Thompson. Thompson, who served as a lead independent director of Microsoft's Board of Directors, led the search for the next chief executive of the tech giant.

Glass Lewis is one of the companies who had been providing recommendations to company shareholders. Majority of the shareholders heed Glass Lewis' advice as it is based on the guidelines of corporate governance. However, some large investors would choose not to follow advisory firms' advice.

On Monday, Glass Lewis suggested in its note to clients that Thompson's role at Microsoft would have a possible conflict of interest. Thompson is chief executive of cloud-computing firm Virtual Instruments. Virtual Instruments had been supplying Microsoft with licenses and devices. In a Microsoft yearly proxy filing, Virtual Instruments received USD2.3 million from Microsoft for supplying hardware and software licenses. The amount accounted to less than 5% of Virtual Instruments' yearly revenue.

When asked for comment about Glass Lewis' note, representatives of Microsoft did not reply to Reuters' request immediately.