The military's third-ranking general resigned Monday, angrily accusing President Corazon Aquino of favoritism in her selection of a new military chief.

The issue of military promotion is sensitive in the Philippines, where favoritism under the late President Ferdinand Marcos provoked the 1986 mutiny that propelled Aquino to power.Aquino on Saturday named army commander Maj. Gen. Lisandro Abadia, 53, to replace retiring Lt. Gen. Rodolfo Biazon as armed forces chief of staff. The appointment is subject to congressional approval.

Maj. Gen. Alexander Aguirre, deputy chief of staff and a candidate for the position, accused Aquino during a news conference Monday of playing politics with seniority in appointing Abadia.

"With all candor and honesty, I frankly say to you I cannot believe in the wisdom of your judgment, for it is unfair and unjust," Aguirre said in an open letter to Aquino.

Abadia had been the most junior of five leading candidates, including Vice Chief of Staff Maj. Gen. Guillermo Flores, who holds the second-ranking post in the military and had been considered the front-runner.

Aguirre said Flores was the most qualified officer based on his experience and grade.