‘‘I came to understand that providing payment services to online gambling businesses serving customers in the United States was wrong,’’ Lawrence said prior to entering his plea.

Lawrence, 47, faces as much as five years in prison on the charge. Sentencing is set for Oct. 29.

John David Lefebvre, another Neteller founder, and Lawrence were arrested and charged with conspiracy in the matter in January. Lefebvre is awaiting trial.

As part of his plea agreement with the government, Lawrence agreed to cooperate with its investigation and agreed to a forfeiture of $100 million.

Lawrence, who lives in the Bahamas, was Neteller’s chairman until May 2006 and left its board last October, while Lefebvre was the company’s president from October 2000 to 2002 and served on the board until December 2005.

Neteller, which is publicly traded in London, has said Lawrence and Lefebvre are no longer affiliated with the company. Neteller has stopped handling transactions involving online gambling from U.S. customers.

Electronic Clearing House Inc., another online payment processing company, entered a nonprosecution agreement with the government in March and agreed to disgorge $2.3 million. Neteller was one of its customers.

U.S. authorities have cracked down on online gambling in recent months, arresting executives of some overseas online gambling firms when they travel to the United States.

President Bush signed into law legislation in October that makes it illegal for banks and credit card companies to process payments from U.S. customers to online gambling sites.