Washington (CNN) -- A Somali suspect pleaded guilty Wednesday to conspiracy to commit piracy in the November 2008 takeover of a merchant ship in the Gulf of Aden, the U.S. attorney's office for the District of Columbia announced.
Jama Idle Ibrahim also pleaded guilty in a plea deal to a charge of conspiracy to use a firearm during a crime of violence, officials said.
"According to the plea agreement, the parties agree that a 25-year sentence is appropriate," a statement from the U.S. attorney's office said. No date was set for the sentencing on those charges.
Ibrahim was among a group of Somali pirates who boarded and seized the Danish-owned cargo ship M/V CEC Future on November 7, 2008, the U.S. attorney's office said in a statement of facts.
The pirates demanded and received an unspecified ransom and "stole money, food and supplies from the vessel," the statement said. The pirates released the ship, cargo and crew after receiving the ransom in mid-January 2009.
Ibrahim, also known as Jamaac Ciidle, pleaded guilty last month in a federal courtroom in Norfolk, Virginia, in another case, admitting he had intended to seize a U.S. merchant vessel on April 10 and hold it for ransom.
Ibrahim and five other would-be pirates learned too late they had instead pulled alongside a U.S. Navy dock landing ship, the USS Ashland, and they were captured.
A statement by the Justice Department said the government and defense agreed to recommend a sentence of 30 years in prison for Ibrahim in the Navy case. Sentencing was set for November 29.
The attempted attack occurred in the Gulf of Aden between the Horn of Africa and the Arabian Peninsula.
Ibrahim is one of 11 Somalis sent to Norfolk for prosecution in two attacks. Five others are charged in connection with an April 1 attack on the Norfolk-based frigate Nicholas.
As part of Wednesday's plea agreement, Ibrahim pledged to work with U.S. authorities on any future investigations.