WM Morrison Supermarkets Plc is leading a group of U.K. retailers seeking to add as much as 1 billion pounds ($1.6 billion) to the amount it’s seeking from MasterCard Inc. in an antitrust suit over payment fees.

The retailers are aiming to extend damages as far back as 1992. They said MasterCard’s conduct meant that the normal six- year limit on damages didn’t apply, according to documents from a pre-trial hearing in London today.

“This is deliberate breach of competition law,” said Fergus Randolph, a lawyer for WM Morrison, seeking a court order forcing MasterCard to hand over internal e-mails. He said the payment company had tried to conceal information about how it set the fees.

The lawsuit is one of dozens filed by retailers alleging that MasterCard profited from unlawful “interchange fees” on consumer purchases. Wal-Mart Stores Inc.’s Asda and Deutsche Bahn AG have also sued in the U.K. over the fees, which have faced a clampdown from European Union antitrust authorities.

Spokesmen for MasterCard in London didn’t immediately respond to an e-mail seeking comment. In court documents from today’s hearing, MasterCard said allegations it had deliberately concealed information were “fanciful.” It said there wasn’t time to search internal messages before a court hearing scheduled for January on whether the six-year limit applied.

The court’s decision in January “could affect the quantum of the claims by more than 1 billion pounds,” WM Morrison said in its legal documents. If the limitation applies, the retailers will only be able to claim for breaches starting in 2006.

EU Court

European retailers have campaigned for years against card fees to process debit- and credit-card payments. In the EU, they are set by MasterCard and Visa Europe Ltd., which own the payment networks and pass the money to the banks.

MasterCard suffered a defeat at the EU’s top court earlier this month when judges said the Purchase, New York-based company failed to show benefits to justify its system of levies.