eBay is in talks to acquire StumbleUpon, a Web site rating system, according to the blog Techcrunch.
Citing an unnamed source, the blog reported Wednesday that Google and AOL have also expressed interest in StumbleUpon.
Founded by a group of Canadians, the company combines a search algorithm and user recommendations to help users discover new sites. On its site, StumbleUpon said it has 2.1 million users.
GigaOm, another blog, reporting that the asking price for StumbleUpon is between $40 and $45 million.
According to ComScore, StumbleUpon has recently seen a sharp rise in traffic, tripling the number of page views in the span between January and March. During the same period, the site's number of unique visitors jumped from 500,000 to 900,000.