Online merchants may send PayPal Inc. transactions through First Data Corp. under a new payment service the transaction processor and CardinalCommerce Corp. announced Monday.

Participating merchants must use First Data's Compass processing platform, which the Atlanta company designed for card-not-present transactions. CardinalCommerce, an online payments company in Cleveland, supplies the connectivity that enables this service.

Merchants using the Compass platform had required a separate connection to PayPal to accept its transactions. Now, with their PayPal transactions processed through Compass, they can receive consolidated transaction reporting and reconciliation, Tim Sherwin, CardinalCommerce executive vice president and chief marketing officer, said in an e-mail. "Any merchant using First Data today and that is either supporting alternative payments or has plans to will be the obvious candidates" to use the service, Sherwin said, declining to say how much the service costs.

Two Internet retailers already are using the service, but Sherwin declined to name them.

Merchants want alternative-payment choices and traditional payment brands, and they want the service to be as easy to use as possible, according to First Data, a unit of the private-equity firm Kohlberg Kravis Roberts & Co.

"With a multitude of alternative-payments options available to merchants, and based on the vertical that they are servicing, this offering makes it easier to integrate alternative payments into the merchant's current electronic payment systems," a First Data spokeswoman said.

Merchants using the Compass platform also may accept PIN-less debit payments, prepaid cards, electronic checks and Google Checkout transactions, First Data said. PayPal is a unit of eBay Inc.