Chile said today it formally asked Britain to allow Augusto Pinochet to return home because of his age and failing health, a new twist in the extradition saga two days before the first anniversary of the former dictator's arrest.

Chilean Foreign Minister Juan Gabriel Valdes said the formal government petition requesting the return of Pinochet has been presented to Britain's Foreign Office to be relayed to the Home Office, which has authority over extraditions.

Clarifying the confusion over whether Britain received the request to consider humanitarian grounds for halting extradition proceedings against the retired general, Valdes told a news conference that the document was sent to London's Foreign Office to be passed on to Britain's Home Secretary Jack Straw--the correct diplomatic route between countries.

"The document has been handed over to the Foreign Office in accordance with communications between two governments, so that the Foreign Office hands over the document to the Home Office," Valdes said.

On Saturday, Pinochet, 83, will complete one year under house arrest in London. He was detained Oct. 16 last year at the request of a Spanish judge who wants Pinochet, who ruled Chile with an iron fist from 1973 to 1990, sent to Madrid to face charges of torture in the latter part of his rule.

"What is requested is that the [British] home secretary considers, in accordance with faculties given to him in the law, a decision of a humanitarian nature," Valdes told Radio Cooperativa in a live broadcast. "We are not saying when London must consider it." Valdes added that the petition had been supported by recent medical reports that "show a deterioration [of Pinochet's health] in the last month."

The humanitarian request was somewhat expected in Chile as the government has long argued that Britain should stop the extradition because of Pinochet's frail health and old age. The former commander in chief of the army has diabetes and a pacemaker, and his doctor says Pinochet is "permanently giddy" from the effects of two apparent strokes last month.

Straw has refused to consider humanitarian grounds for releasing Pinochet until judicial proceedings have ended. Straw has the final say in extradition cases and can block them on humanitarian grounds.