The pressure must be getting to Microsoft's very own bald eagle Steve Ballmer as he issued a stinging public rebuke - for the first time - to dissenting investors calling for his head, and used the soon-to-be released fiscal 2011 results to back up his reputation.

According to reports in the Seattle Times, Microsoft's CEO shouted at a captive audience attending a civic bash in the city's Rotary Club yesterday.

"You tell me if I lack energy, conviction or we're not driving change we need to drive," he bellowed.

Calls for Ballmer to quit the firm have been growing in recent weeks - including from high profile hedge fund bigwig David Einhorn, president of Greenlight Capital - given the firm's share price stagnation, and IBM and Apple's overtaking it in terms of market capitalisation.

The nine-strong board continues to support him.

To justify his top seat, Ballmer then gave a sneak preview of Microsoft results for the year ended 30 June, not due to be published for some weeks yet.

"There's a reason why we'll do almost $70bn in revenue this year and we'll make over $20, whatever, $26, $27bn in profits," he added.

Redmond then clarified post-event to the ST that the big cheese was actually referring to operating profits of $26bn to $27bn, slightly lower than analyst estimates of $27.2bn and sales of $69.8bn.

Microsoft refused to comment. ®