President-elect Tancredo Neves was taken to a hospital here late last night and reportedly underwent surgery for an intestinal inflammation only hours before his scheduled inauguration. Political sources said it was unclear whether he would be able to take office today.

Neves, 75, was taken to the Hospital de Base here at around 10 p.m. last night, according to his spokesman, Antonio Britto. Britto originally reported that Neves was suffering from appendicitis. However, after surgery was completed early this morning, Britto said doctors had diagnosed Neves' condition as diverticulitis, an inflammation of the intestine that produces symptoms similar to those of appendicitis.

Neves was scheduled to be inaugurated this morning as Brazil's first civilian president after 21 years of authoritarian military rule. Political sources here said if he were unable to take office, control of the government would be assumed by Jose Sarney, the vice president-elect who is also due to be inaugurated today.

Shortly after 2 a.m. this morning, Neves' grandson and personal secretary, Aecio Cunha Neves announced at the hospital that the president-elect would be sworn in. "Brazil can breathe easily," he said. However, other government sources maintained that Neves, although in good condition after his operation, would be unable to take office today.

Britto said that "some adaptations" would have to be made in the scheduled inauguration ceremonies. There was some speculation that Neves might be sworn in at the hospital.

Outgoing President Joao Figueiredo, a retired general, and Vice President Aureliano Chaves, are required by the Brazilian constitution to leave office today, the sources said.

Neves, chosen president in an indirect election Jan. 15 by a special electoral college, was reported by his physician to be suffering from a cold since Wednesday.

Leaders of Brazil's armed forces repeatedly have promised to respect the new civilian government and there was no indication this morning that the military intended to intervene in the inauguration.