San Francisco, Calif. — Twitter is believed to be in the process of completing an $800 million funding deal that will value the company at nearly $8 billion, AllThingsD reported Thursday.

Current investors and employees can cash out at $400 million, The other $400 million in this two-stage deal will go towards the company itself, helping the fast-growing social network to build a lucrative business model and strengthen its infrastructure.

Expected to be completed within the next two weeks, the $8 billion is double the valuation Twitter had in January. Although the company has no current plans to go public, rumors say an acquisition offer from Google may arise in the future.

Digital Sky Technologies, which invested $200 million in Facebook in 2009, is participating in the deal. Other investors include Benchmark Capital, Union Square Ventures, Spark Capital and several other venture firms, as well as a few prominent angel investors.

The news comes at a time when the company has lost four key product managers, including Jack Dorsey, Josh Elman and Kevin Cheng. Twitter refused to comment on specific individuals, but added that “some people have left the company and we appreciate their contributions.”

Related Links: (AllThingsD) (TechCrunch)