(Adds background paragraphs 7-10)

MEXICO CITY, May 10 (Reuters) - The United States has requested the extradition of imprisoned Mexican drug lord Benjamin Arellano Felix so he can be tried in California on trafficking charges, his lawyer said on Thursday.

One of the last captured Mexican drug barons yet to be tried in the United States, he ran the Tijuana-based Arellano Felix cartel with his brother Ramon starting in the late 1980s.

Ramon died in a shootout with police in 2002 and Benjamin was arrested shortly afterward.

His lawyer, Americo Delgado, told Reuters that Arellano Felix was notified on Wednesday of the extradition request from a federal court in San Diego. He plans to submit an appeal next week, Delgado said.

Mexico extradited 15 jailed drug traffickers to the United States in January, including Osiel Cardenas, accused of running the powerful Gulf Cartel, and Hector "El Guero" Palma, a senior member of the Sinaloa cartel.

Last month, a Mexican judge sentenced Arellano Felix to five years in prison for arms possession. He faces more time for outstanding charges such as organized crime activities and drug smuggling.

Washington, which had a $2 million bounty on Arellano Felix's head in the United States until his capture, has sought his extradition for more than a decade.

The U.S. Drug Enforcement Administration also links Arellano Felix to the slaying of a Roman Catholic cardinal in 1993 in a case of mistaken identity.

Gunmen for the Tijuana cartel apparently had meant to kill rival drug lord Joaquin "Shorty" Guzman at the airport at the Mexican city of Guadalajara.

U.S. officials say the Arellano Felix cartel, which dominates the flow of narcotics into California, was severely weakened by Ramon's death and Benjamin's capture, along with the arrest of another brother, Francisco Javier Arellano Felix, last August.

Mexican drug trade experts disagree, saying 46-year-old Enedina Arellano Felix and several younger members of the clan have stepped up to leadership posts.

President Felipe Calderon has sent out thousands of troops to tackle Mexico's violent drug cartels, which were behind some 2,000 gangland-style killings last year. But the increased firepower has failed to contain the violence, including a recent wave of attacks on senior police officers.

Drug gang-related deaths number some 800 so far this year.

AlertNet news is provided by