Popular micro-blogging site, Twitter, is raising around $50 million at a $1 billion valuation, TechCrunch's Michael Arrington reports, citing multiple sources.

According to the report, Twitter CEO Evan Williams disclosed the information at a recent employee meeting.

Earlier this year, Twitter raised $35 million which was led by Benchmark Capital and Institutional Venture Partners.

Since the company is private, it offers no material revenue for review, but it does seem this fast-growing Web 2.0 company has big plans that require large sums of capital.

Watch this space.