Auction giant eBay is preventing its sellers from using Google's rival Checkout service.

Google Checkout allows consumers to buy products online without having to reveal any sensitive financial information to sellers. 

The search firm started offering the service to online shops last month. It had previously been used only to pay for Google advertisements and offerings from Google Video.

Google Checkout is seen as a competitor to eBay's PayPal service, which allows for payments between individuals, as well as between consumers and merchants. 

Citing PayPal's ease of use and fraud protection features, eBay states on the Rules For Sellers section of its website that it "strongly encourages sellers to offer payments through PayPal". 

Further down on the same page, eBay lists Google Checkout among a series of services that are prohibited.

Offering buyers the option of using any of the blacklisted payment services can result in a cancellation of the listing, limits on account privileges, account suspension and loss of PowerSeller status, eBay warns.

EBay spokeswoman Catherine England told vnunet.com that Google Checkout lacks a track record as a secure and reliable consumer payment service. 

She acknowledged that Google is an established brand that has consumer confidence, and that Google had been using the Checkout service before launching it as a merchant offering last week.

"But making sure that each payment model offers substantial protection is important for our buyers and sellers," said England. "We are using the same criteria to evaluate all payment services."

EBay allows another 13 payment services in addition to PayPal, including Allpay.net and MyCheckFree. 

Google Checkout is likely to be deemed an approved payment service once it has a proven track record, according to England.

The spokeswoman was unable to say when this would occur, but claimed that eBay will continue monitoring the service and will listen to feed back from its users.