MADRID (Reuters) - A Spanish political activist who was convicted in the death of prominent Cuban dissident Oswaldo Paya in a car wreck in Cuba in July will return to Spain to serve out his four-year prison sentence, the government said on Friday.

Angel Carromero, a leader of the youth wing of Spain's ruling People's Party, was tried in Cuba and found guilty of reckless driving in the accident, which killed one of the most important leaders of Cuba's small opposition community.

Spain has been working since then to bring Carromero back to serve his time under an agreement by which both countries allow their respective citizens to be imprisoned in their homeland.

"Today Angel Carromero's transfer has been authorized, so that he serves here the sentence imposed by Cuban authorities," Spanish Vice President Soraya Saenz de Santamaria told a news conference.

Saenz de Santamaria said Spain's consul general in Havana had signed a memorandum with Cuba regarding the transfer but she said she could not confirm the date when he would return.

Carromero, 26, was driving near the eastern city of Bayamo on July 22 when he lost control of his small rental car and ran into a tree.

The two people in the front seats of the car survived with minor injuries - Carromero and Jens Aron Modig, a youth leader for Sweden's Christian Democratic party. But two back-seat passengers were killed - Paya and another dissident, Harold Cepero, 31.

Paya's family and other dissidents charged that Cuban government agents ran the car off the road but Carromero and Modig have said no other vehicle was involved.

(Reporting by Emma Pinedo and Fiona Ortiz; Editing by Angus MacSwan)