Groupon has walked away from Google’s $6 billion takeover offer, according to a person close to Groupon. The rejection at least temporarily thwarts Google’s efforts to buy the social buying site, which would have been its largest acquisition to date.

According to several people with knowledge of the takeover talks but who were not authorized to speak publicly on the matter, Google was eager to purchase the fast-growing start-up, based in Chicago, raising its bid at least once during negotiations.

Options for Groupon include the possibility of staying independent but securing a significant investment, as its rival LivingSocial did by accepting $175 million from Amazon this week.

Groupon’s chief executive and founder, Andrew Mason, has also expressed his interest in taking the company public with a share offering.

Representatives for Google and Groupon declined to comment on the matter Friday evening.

The rejection was first reported by The Chicago Tribune’s Breaking Business Web site on Friday evening.

Groupon’s subscriber network has expanded to 35 million users in 300 markets in North America, Latin America and Europe. It is pulling in more than $1 billion in annual revenue. It is that high-octane growth that most likely stands in the way of a deal. During discussions, estimates of Groupon’s revenue continued to rapidly climb, weakening the value of Google’s offer, according to a person with knowledge of the talks.

Analysts say that Google may not be quick to raise its bid. “If Groupon rejected this number, it’s likely done unless Google is willing to really raise the numbers,” said Greg Sterling, founder of Sterling Market Intelligence, a San Francisco company that researches local markets and the Internet.

“What would it take? $7 billion? $8 billion? Google’s got $30 billion, which is a lot of cash, but when you’re approaching a third of that, that’s asking for a lot.”

Instead, Google could acquire one of Groupon’s larger competitors, such as LivingSocial, BuyWithMe or Tippr.

The dissolution is reminiscent of Google’s attempt late last year to purchase Yelp, the Web site that lists reviews of local businesses. Google walked away from that deal for reasons that were never explained. The offer for that proposed acquisition was said to have been around $500 million.

If completed at the offered price, the Groupon deal would top Google’s $3.1 billion purchase of DoubleClick in 2007.

The acquisition also would have yielded an immediate lucrative payout for the company’s 30-year-old founder and its roster of financiers, which includes Accel Partners, Digital Sky Technologies and New Enterprise Associates, who have invested more than $170 million in the company to date.

Google had set its sights on the hyperlocal market for neighborhood mom-and-pop shops, where it sees a largely untapped group of business customers and advertisers. Groupon, which offers discount coupons, could provide Google with specific insight into consumer spending habits as well as provide access to a large fleet of salespeople with intimate knowledge of local markets.

“This is a more challenging proposition for Google, in a way, because Groupon is a local sales and marketing company,” Mr. Sterling said. “There’s no technology that can do that, for now, especially the sales channel. It would have been a cultural change for Google to have access to that sales team that Groupon represents.”