CHICAGO — Groupon Inc. is in talks with banks on a potential initial public offering that would set the value of the online-coupon firm at as much as $25 billion, Bloomberg reported Thursday.

Groupon may begin trading as a public company this year, according to the report.

In December, the daily discount provider turned down a $6 billion offer to be bought by Google.

Groupon, which has 70 million online users and reaches more than 500 markets, was valued at about $1.3 billion last April, when it raised $135 million from investors.