President-elect Tancredo Neves underwent emergency surgery today to repair a hernia. It was his fourth operation in less than three weeks.

Presidential spokesman Antonio Britto said Neves, who had been recovering slowly from a five-hour operation a week ago to remove a damaged section of intestine and staunch a hemorrhage, complained of sharp pains.

The medical team discovered that a loop of intestine had become trapped by scars in the abdominal wall -- opposite the recent incisions -- arising from a hernia operation many years ago. Because of the 75-year-old Neves' weakened state, Britto said, the 100-minute operation was performed without a general anesthetic. The president remained cheerful, talking to surgeons during the operation, Britto added.

"The operation was a complete success," said Sao Paulo state Gov. Franco Montoro after visiting the hospital.

Neves was operated on for diverticulitis on March 14, which prevented his taking office the next day. Infection troubles have kept him hospitalized since.

In Brasilia, acting President Jose Sarney, 54, continued at his desk and was not expected to travel to Sao Paulo. Sen. Fernando Henrique Cardoso, congressional leader of the coalition government, told reporters that "nothing changes" politically because of the operation. "The collaboration of all parties guarantees continuity," he said.

Because of the latest operation, metalworkers' unions here agreed to call off a strike at the request of the labor minister.