New York Times News Service | Groupon, the social buying site that spurned a $6 billion offer from the search giant Google, is pushing ahead with plans for its initial public offering, a debut that could value the company at $15 billion or more.

The company, which just raised a record $950 million from big investors, discussed a public offering with bankers this week, according to two people with knowledge of the deal who were not authorized to speak publicly on the matter. Banks are pitching Groupon on dizzying valuations at which they expect to take the company public, with many at $15 billion. Get the full story »