Troitino, a member of the Euskadi Ta Askatasuna separatist group, was wanted in Spain on terrorism charges for a number of bombings in 1982 and 1984 -- including an explosion on a bus in the Plaza Republica Dominicana in Madrid that killed 12 Guardia Civil officers and injured 50, ThinkSpain reported Saturday.
He was released April 13, 2011, after serving 24 years of a 30-year sentence on those charges.
The National Court of Spain appealed the reduction of Troitino's prison term and called for his arrest but he had already fled to London.
He was arrested in an apartment near Heathrow Airport in June 2012 with fellow separatist Ignacio Lerin.
Michael Snow of Westminster Court rejected defense lawyers' argument returning Troitino to Spain would violate his human rights. Snow said the deportation order was "was in keeping with the requisites stipulated by the European Convention."
Defense lawyers have seven days to appeal the court's decision.