MANILA, Philippines (AP) _ A Filipino general claims former first lady Imelda Marcos and the U.S. government secretly supported a coup attempt last December that was put down with the help of American jets.

Brig. Gen. Alejandro Galido made the allegations in a sworn statement released Wednesday by the Department of Justice. Galido said he was aware of plans for the Dec. 1-9 coup attempt and reported the conspiracy to Chief of Staff Gen. Renato de Villa.

It was not known why the government released the statement, but it followed disclosures earlier this week that businessmen and others had supported the coup attempt. One businessman was arrested.

The statement is part of a government investigation into the coup attempt, and Galido has been described by government officials quoted in newspaper reports as a government spy.

There was no indication in Galido's statement why U.S. planes intervened in the coup if the United States secretly supported it.

Galido said a U.S. Air Force colonel, Harold Magelo, told him in July that U.S. intelligence ''supports the overthrow'' of President Corazon Aquino.

Galido said Magelo, who identified himself as a member of the Defense Intelligence Agency, promised ''to deliver ... shipments of firearms, ammunition, anti-tank missiles'' and other weapons.

He also said U.S. Ambassador Nicholas Platt held a party at his home in August during which conspirators received written instructions from Brig. Gen. Edgardo Abenina, who was held at a military camp for involvement in a coup attempt in 1987.

The latest attempt was launched shortly after midnight on Dec. 1, when thousands of mutineers attacked military and media facilities, seized aircraft at Villamor Air Base and staged air strikes on the presidential palace.

U.S. F-4 Phantom jets from Clark Air Base flew air cover in support of government forces and prevented the mutineers from continuing their air strikes. At least 113 people were killed and more than 600 injured before rebels surrendered their last stronghold Dec. 9.

Platt is in the United States on vacation. Spokeswoman Vicky Middleton said a statement would be issued later.

Mrs. Aquino's spokesman, Adolfo Azcuna, said the government would not comment on Galido's statement until a presidential commission established to investigate the coup attempt submits its final report.

Galido also said Mrs. Marcos supported the conspiracy and promised to pay about $475,000 to the coup plotters if she could return to the Philippines.

Mrs. Marcos fled the country in 1986 after her husband, President Ferdinand Marcos, was ousted in a popular uprising. Marcos died in Hawaii in September, and Mrs. Marcos went on trial in New York City Tuesday on racketeering charges.

Galido said he spoke with Mrs. Marcos several times by telephone before Marcos' death, and she urged him to press ahead with the plans so the former president could die in his homeland.