President Ferdinand Marcos emerged from medical seclusion today, hastily convening his Cabinet and signing a parliamentary bill in a televised ceremony as part of an apparent attempt to scotch two weeks of rumors about serious health problems.

The television appearance followed publication of a medical bulletin describing the president's condition as "stable" but noting that he "still has a little asthma and pulmonary secretions which require aerosol treatment and chest physiotherapy."

A presidential spokesman said today that Marcos was "recovering from the flu."

The ceremony was Marcos' first meeting with his Cabinet and legislators since his doctor advised him "to refrain from strenuous activities and stay in seclusion to speed up his recovery from his respiratory ailment," a presidential palace press statement said. The signing of an appropriations bill for the $2.9 billion 1985 budget was attended by more than two dozen Cabinet officers, legislators and other government officials.

However, opposition legislators complained that, in a break with tradition, their representatives on the appropriations committee had been excluded from the ceremony.

Information Minister Gregorio Cendana said this was unintentional and that Marcos had called the meeting this morning at short notice for around midday. He said Marcos met the invited officials for about 40 minutes and now was "in a hurry to go back to work" after a bout of flu that "could have developed into bronchitis."

"We hope there will not be any relapse," Cendana said.

In the government videotape, shown on television news bulletins during the day, Marcos was seated in his Malacanang Palace office wearing a traditional barong shirt and a white jacket. The invited officials applauded him after the budget-signing ceremony and dispersed.

Defense Minister Juan Ponce Enrile, who was among those present, said Marcos "showed a certain amount of weakness" because of "some health problems" lately.

"His voice was a little weaker than unusual," Enrile added, but now "he's up and about."

Some opposition figures were not satisfied, however.

"I would have wanted to see how he looks," said opposition legislator Homobono Adaza. "Then we could have informed the people." Adaza said he was one of nine opposition members of the appropriations committee who were informed of the ceremony too late to attend.

Since Marcos went into seclusion Nov. 14, a day after meeting U.S. Sen. Christopher Dodd (D-Conn.), Manila has been rife with rumors about the president's health. Aside from being reported dead, he was rumored to have undergone a kidney transplant operation, a heart bypass, or perhaps a tracheotomy.

An opposition legislator also put out a story that Marcos was going to the United States for medical treatment and leaving the government in the hands of a civilian-military junta.

All the rumors were officially denied.

That the rumors persisted is seen here in part as a measure of the government's low credibility generally, and its failure in particular to explain some odd coincidences at Manila's kidney center. The transfer of patients at the center to an adjoining building and orders for half the hospital's personnel to go on leave preceded "repairs" that sealed off the center's main building and the stationing there of an unusual number of security guards.

A team of American kidney specialists was also reliably reported to have visited Manila for about 10 days while Marcos was in seclusion.

According to medical sources, Marcos long has suffered from lupus erythematosus, a degenerative kidney disease. He is reported to have regularly undergone kidney dialysis and treatment with drugs, including steroids, which have accounted for occasional puffiness in the face.

Marcos' health became a subject of rumors and intense speculation last year around the time that his political arch rival, opposition leader Benigno S. Aquino Jr., was assassinated on his return to the Philippines from self-exile in the United States.

Then as now, the rumors underscored concerns about the succession to Marcos, who has ruled this nation of 52 million people for 19 years. Since Aquino's assassination, a succession process has been formally adopted, but it is considered somewhat shaky.

Until the vice presidency is restored in elections scheduled for 1987, the president is to be succeeded by speaker of parliament Nicanor Yniguez, a political nonentity, as an interim leader for up to 60 days, by which time a special election should be held.