While media giant will pull the social gaming acquisition trigger first? Playdom, one of the largest social game developers on the Facebook platform, has been talking to Disney about an acquisition, sources tell TechCrunch and VentureBeat. Rumored sale prices start at the company’s previously-estimated $345 million valuation from its last funding round, and go up past $600 million.

While Playdom has been busy buying smaller developers in the last several months, we’ve heard rumors about it selling during the same period — including through the past few days. It’s possible that the company is talking to other suitors too. It wouldn’t be the first time as we heard that Playdom was talking to News Corp, back in March:

Indeed, we’ve been hearing continued rumors in recent months, the latest of which is News Corp’s interest in Playdom, one of the largest developers on the MySpace developer platform and an increasing presence on the Facebook Platform. Given Zynga’s size and Playfish’s recent acquisition by Electronic Arts, Playdom and fellow developer CrowdStar are two of the more likely acquisition candidates over the coming year. And Fox’s involvement would certainly make the dynamics between it and Facebook even more interesting.

CrowdStar was in talks with Microsoft, Tencent and other suitors earlier this year, according to other reports and one of our sources. The company is still independent, though.

The two other market leaders on Facebook’s platform, Playfish and Zynga, are both accounted for. Playfish sold to game giant Electronic Arts last fall for up to $400 million. Zynga, the largest social gaming company, has been busy raising money (or maybe its early investors have been busy selling off chunks of their stock?). Anyway, after having talked to a range of companies about selling itself last year, it appears to have hundreds of millions of dollars available, and a valuation of more than $6 billion, we’ve heard from industry sources. It is still busy trying to buy smaller social gaming companies, these people say.

Overall, Playdom is in one of the better positions among social game developers, with historical strength on MySpace, mobile forays, and two solid Facebook hits this year, city-builder Social City and soccer game Bola. With some $76 million in funding, and stats that imply significant revenue — it currently has 41.3 million monthly active users and 4.84 million daily active users on Facebook alone, according to AppData — it could very well stay independent, and eventually make an initial public offering like it has hinted at.

We also expect media companies like Disney, if not other game developers and international market leaders like Tencent, continue looking at buying social game developers, even as many of them test out their own apps.

For Inside Network’s in-depth research on the social gaming market, check out Inside Virtual Goods: The Future of Social Gaming 2010