The Federal Reserve's decision on debit interchange fees seems to exclude eBay Inc.'s (NASDAQ: EBAY) PayPal from being treated as a "payment card network", Jefferies said in a note to clients.

"After discussions with eBay, Jefferies' Payment Services research team (and a review of the complex 300+ page document), we believe that PayPal will not be affected by the new cap rules, (except for its co-branded Mastercard debit cards, which are immaterial to financial results)," said Youssef Squali, an analyst at Jefferies.

Squali said the primary reason Paypal does not seem to fall under the definition of a "payment card network" is that for any PayPal transactions that take place between a merchant, a customer and the customer's bank with PayPal as the payment operator, the transaction is settled on PayPal system (versus being routed to the individual parties), whereby PayPal makes the appropriate debit (customer) and credit entries (merchant).

Under the non-traditional payment systems section of the new rules, "an entity is not a 'payment card network'... when the entity does not send the transaction information and data to another point and instead merely makes book-keeping entries". As such, PayPal is considered a Three Party System, exempted under the new rules, Squali said.

The much-debated proposal to implement the Durbin amendment cap on debit-card interchange fees came in focus once again Wednesday as Fed raised the debit interchange rate cap to 21 cents.

Squali said the Fed's proposal to cap interchange fees to $0.21/$0.22 (from about $0.44) should result in lower processing costs on debit transactions for PayPal. While eBay does not break out the funding mix, Squali believes debit accounts for 10 percent to 15 percent of PayPal's total transactions, with the remainder being ACH and credit.

Squali said assuming an effective interchange rate of 100 to 120 basis points on debit-funded transactions on PayPal, and given PayPal's average transaction size of $65 (his fiscal 2012 estimates), the proposed cap should lower debit processing costs by $0.44 to $0.57 per transaction (all else constant).

With an estimated 2.22 billion payment transactions flowing through PayPal in 2012 (Squali's estimate), it should yield about $74 million to $96 million in cost savings.

"We believe that PayPal would look to pass much of the savings on to clients (merchants) to further improve its competitive advantage as a lower cost payment option. Assuming 70 percent of the estimated cost savings are passed on by PayPal to merchants, there may be a about $0.01 in positive impact to 2012 EPS," said Squali.

eBay stock closed Wednesday's regular trading up 6.56 percent at $30.86 on the NASDAQ Stock Market. During the pre-market trading on Thursday, the stock rose 1.23 percent to $31.24.