Groupon’s non-IPO raises $500 million, with $450 million to go

Welcome to the age of the stealth IPO.

Groupon, the fast-growing purveyor of online discounts from local businesses, has confirmed through a filing with the Securities and Exchange Commission, that it has authorized a new $950 million financing round. (Groupon’s plans first came to light earlier this week through a related filing in the state of Delaware, where Groupon is incorporated, discovered and analyzed by VC Experts.)

Of the $950 million, $500 million has already been raised from new and existing investors. New investors, Fortune reports include, T. Rowe Price, Morgan Stanley, and Fidelity Investments — all players one would expect to see involved in an initial public offering.

The funds involved are staggering, ranking among the largest venture-capital financings ever. And an estimated $345 million is going to cash out insiders. It’s important to note that that’s an estimate: Groupon is reportedly making a tender offer to buy back up to 15 percent of current investors’ shareholdings. That estimated $345 million could represent the maximum if CEO Andrew Mason (pictured here, in a thoroughly fictional Photoshop), Lightbank’s Brad Keywell and Eric Lefkofsky, Accel Partners and other prominent shareholders sold a full 15 percent of their holdings.

But it’s still notable that Groupon is raising a massive warchest and offering to cash out insiders, all without the usual mechanism of an initial public offering.

Here’s my take: Groupon is satisfying restive shareholders who may wish it had taken Google’s $6 billion offer, at the same time that it’s gathering an intimidatingly large cash pile to buy up overseas knockoffs of its daily-deal site and scare off domestic competitors like LivingSocial and BuyWithMe out of the market. Meanwhile, it’s building a sales force to reach more and more cities and beefing up its technology to personalize offers and satisfy demand from businesses.

And this stealth IPO has one more advantage: There’s nothing preventing Groupon from doing a real IPO in 2011. If anything, the reassuring cash pile makes it a more attractive investment.