EBay on Monday said it is launching its previously announced instant-purchasing service to supplement bid-and-wait online auctions, pitting it more directly against online retailers. The San Jose, Calif.-based company said the service, known as eBay Express, aims to woo convenience-oriented shoppers interested in snap-buying decisions on fixed price products rather than its traditional online auction format.

The site went public over the weekend and features 10 million items for sale initially, simply by tapping its existing base of eBay store sellers.

The U.S. version of eBay Express is operating in "preview mode" to give hundreds of thousands of sellers that take part in its eBay Stores affiliate program the opportunity to test out the site and consider listing their own product inventory on it. A German version of the site will be offered in the third quarter.

"We are taking this subset of eBay and marketing it in new ways to both existing eBay buyers and new audiences," Jamie Iannone, the Director in charge of eBay Express said.

In the meantime EBay has been in talks with both Yahoo and Microsoft to determine whether one of them might be a suitable ally against common threats from Google, according a Wall Street Journal report released last week.

"After years of working closely with the search giant, eBay last year became alarmed as Google started assaulting its turf in multiple ways," the report said, including creation of a competing classified advertising service.

EBay's talks with Yahoo and Microsoft began in earnest last fall, the report said, citing people familiar with the discussions.

The report said it remained unclear how much money might be involved and whether the parties have considered a more complex deal, such as one side taking an equity stake in the other.