COLUMBIA, S.C. - Former South Carolina Agriculture Commissioner Charles Sharpe pleaded guilty to an extortion charge Thursday, admitting he took a $10,000 bribe to protect a cockfighting organization from legal trouble.

The 66-year-old Republican was accused of accepting the payoff from an organization involved in breeding and raising birds for cockfighting, which is illegal in the state. He used the money to pay off a debt from his 2002 campaign for commissioner, said prosecutor Mark Moore.

Sharpe also pleaded guilty to lying to a federal officer about his involvement with the South Carolina Gamefowl Management Association.

"I am truly sorry for my error in judgment and ask for forgiveness," Sharpe told U.S. District Judge Cameron Currie.

Prosecutors agreed to drop 10 other charges, including money laundering, in exchange for the plea. They recommended a prison sentence of up to 2 1/2 years, but it's up to the judge who could give Sharpe up to 25 years.

There is no parole for a defendant who pleads guilty. "I understand I am at the mercy of the court," Sharpe said.

Sharpe was suspended following his indictment this summer, and an interim agency head was appointed in September. Sharpe remained free on bond Thursday pending his sentencing hearing, but his guilty plea cost him his office.

He officially resigned Wednesday, said Will Folks, a spokesman for Gov. Mark Sanford. The governor will talk with interim commissioner, Bowman dairy farmer Hugh Weathers, to see whether he would like to serve out the remaining two years of Sharpe's term. If not, the governor could schedule a special election.

Sharpe's attorney Jim Griffin said he advised his client to plead guilty after reviewing the mass of evidence collected against the commissioner.

In November, a former State Law Enforcement Division agent also pleaded guilty to lying to federal investigators about the case. Keith Stokes admitted he lied to FBI agents about whether SLED was investigating a cockfighting ring. Stokes is awaiting sentencing.

Prosecutors, SLED and the FBI said they could not comment about any other charges or arrests in the case.

"This was a long and complex investigation," said SLED Chief Robert Stewart. "The synopsis heard in the courtroom does not describe how difficult this case was to make."

During the two-year investigation, Aiken County law enforcement officers, working undercover for the FBI, recorded conversations with Sharpe, Moore said.

Sharpe lied to the officers, saying the state attorney general had issued an opinion that the fighting, which attracted spectators from multiple states, was legal because it was only used to test the "bloodline" and hardiness of the birds, prosecutors said. But, people paid to enter animals in the competition where the birds were allowed to fight to the death.

Moore said the group wanted Sharpe to use his position as agriculture commissioner to lobby state lawmakers to help regulate their business. "They were really seeking a monopoly on the business," he said.

The arena was shut down in November 2003 and more than 100 people were charged with participating in a cockfight, which is a misdemeanor in South Carolina.

Sharpe served in the South Carolina House, where he was a chairman of the Agriculture Committee, from 1985 until he was elected agriculture commissioner in 2002.