Google's attempt to buy the U.S. local-coupon site Groupon appears to have failed for now, according to reports.

Groupon, whose ties to local merchants and some 18 million subscribers made it a company worth potentially $5 billion to $6 billion US to Google, has decided to stay independent for now, and may pursue an initial public stock offering.

That's according to reports in the Chicago Tribune, the Wall Street Journal and the New York Times that are based on unnamed sources close to the negotiations.

Groupon is based in Chicago.

Messages to Google and Groupon representatives were not immediately returned Saturday.