Speaking at the company's Worldwide Partner Conference in Washington, Microsoft COO Kevin Turner took a shot at Apple on the back of its recent iPhone 4 problems.

“It looks like the iPhone 4 might be their Vista, and I'm okay with that,“ he's reported to have said.

Earlier this week a US consumer report said that it wouldn't recommend buying an iPhone 4 due to the much-publicised issue of signal-loss.

Shares of Apple slid more than 4% on Tuesday based on the report.

“One of the things I want to make sure you know today is that you're going to be able to use a Windows Phone 7 and not have to worry about how you're holding it to make a phone call,” Turner added.

Microsoft is playing catch-up in the smartphone space but has big plans for its Windows 7 Phone, which is due to launch before the end of the year. But that's a long way off. Should Microsoft be acting so cocky when it's got so much to do?