Former Philippine President Ferdinand Marcos, who is listed in critical condition with heart, lung and kidney failure, underwent an operation Tuesday for the removal of an abscess on his pancreas, hospital officials said.

The officials said the operation was not a life-or-death matter for the 71-year-old Marcos. The surgery was not expected to affect his overall condition.Marcos, forced into exile by a popular uprising and an army revolt in February 1986, had a relapse on May 19 at the St. Francis Medical Center and was said by hospital spokesman Eugene Tiwanak to be likely to die at any time.

But Tiwanak said Friday that Marcos, who is visited regularly at the hospital by his wife, Imelda, was looking more alert.

Marcos, who has been in the hospital for more than four months, is attached to a respirator and a kidney blood-cleansing machine and is in an intensive care unit.

One of Marcos's doctors, Azucena Ignacio, said last month Marcos was on a medical roller coaster. "He is really sick and has many problems," she said.

A U.S. government prosecutor said in April Marcos was too ill to stand trial on charges of stealing $103 million from his homeland.