Social gaming company Zynga, which is the force behind sensations like FarmVille and CityVille, continues to be a hit with investors.  Days after rumors indicated Zynga would raise $250 million at a valuation of $7 billion to $9 billion, a new report’s claimed it will actually raise twice that amount at a valuation of $10 billion.

Kara Swisher – who’s pretty much always right about these things – broke the news, citing multiple sources.  So it’s a good bet that the new figures can be accepted in place of the old ones.

Next, Swisher added, "The round includes big institutional investors Morgan Stanley, T. Rowe Price, Fidelity Investments, as well as a token investment from existing venture investor Kleiner Perkins, in order to establish the huge valuation."

That’s an impressive list of organizations.  Together, they’ve backed Amazon, Facebook, Google, Twitter, and just about every other successful tech company around.

Their support of Zynga is likely to create even more interest, then, perhaps further driving up the company’s value ahead of whenever it holds an initial public offering (which a fair amount of gossip slates for early 2012).

Swisher noted, "While some worry about Zynga’s reliance on Facebook, as well as sharing some of its revenue, sources said the company’s sales of virtual goods and advertising is closing in on $1 billion and more annually."