Microsoft blogger Robert Scoble is leaving the company to join Silicon Valley start-up PodTech.net.

Scoble spearheaded the blogging initiative at Microsoft. He is seen as the world's first corporate blogger, a rank-and-file employee providing the outside world with an inside view of a company which has not been sugar-coated by the PR department.

Scoble's willingness to both praise and criticise Microsoft propelled his popularity. Blog search engine Technorati ranks Scoble's site as the world's 22nd most popular blog.

He is often considered the company's third best known employee, behind chairman Bill Gates and chief executive Steve Ballmer.

Scoble started a trend of corporate transparency within Microsoft, and the company now has about 3,000 employees publishing blogs on the MSDN website.

Scoble countered speculation that he had been forced to leave the company. "I love Microsoft and Microsoft did not lose me, at least as a supporter and friend. I am not throwing away my Tablet PC or my Xbox or my other Microsoft stuff," he stated.

"At Microsoft I am encouraged to change the world and make things better for our customers," he added in a reference to the way that the company dealt with his criticism and the topics he covered.

In addition to writing his blog, Scoble worked for Microsoft's Channel 9 developer website. He also was a frequent speaker at blogger conferences and has co-written a book about the phenomenon called Naked Conversations.