Shares in online gambling company Sportingbet PLC, whose chairman is facing charges in the U.S., plummeted 41 percent Monday after they resumed trading.

Sportingbet was trading at 141.88 pence ($2.65) on the London Stock Exchange on Monday, their first trading after being suspended at 239 pence ($4.46) on Sept. 7.

The company's chairman, Peter Dicks, was detained last week in New York following his arrival on a flight from London. Customs officials discovered he had an outstanding warrant issued by Louisiana authorities for illegal Internet gambling.

He was released on $50,000 bail on Friday as he attempts to fight extradition to Louisiana. He is due to attend a hearing Sept. 14 to "consider his transfer" to the southern state.

The May warrant charged Dicks, who lives in London, with gambling by computer, a felony punishable by up to five years year in prison and a $25,000 fine.

"Dicks intends to vigorously contest this," Sportingbet said in a statement.

Dicks, 64, is the second executive of a British Internet sports-betting company to be held in the U.S. after David Carruthers, former chief executive officer of BetOnSports PLC, was arrested in July.

The company fired Carruthers, who remains under house arrest in the St. Louis area awaiting trial, and closed its U.S. Web sites.

Louisiana authorities said more arrest warrants have been issued in connection with the case but declined to provide more information.