MANILA, DEC. 7 -- Former finance secretary Jaime Ongpin, one of the main architects of President Corazon Aquino's economic policy, was found dead today with a single gunshot wound to the head in what police officials and family members described as an apparent suicide.

Ongpin, 49, who was widely known in the international finance community as the Philippines' chief negotiator in the country's debt restructuring talks, had been one of Aquino's most powerful and influential advisers until she fired him three months ago as part of a government shake-up in the aftermath of an aborted Aug. 28 coup attempt.

Ongpin's eldest son, Rafael, was quoted by news agencies as telling reporters that his father had been distraught since Aquino fired him because of intense political pressure. "My father is dead," Rafael Ongpin was quoted as saying. "It is an apparent suicide. He had been unhappy for some time following his end of tenure from the government."

Police officials said a janitor at the building where Ongpin had an office heard a gunshot shortly before 3 p.m. today and found Ongpin slumped over his desk with a .38 caliber pistol in his hand. Ongpin had a gunshot wound in his right temple.

The restructuring agreement, covering nearly half of the country's $28 billion foreign debt, has become Ongpin's most lasting and controversial legacy. While easing somewhat the country's debt repayment burden, the restructuring package also brought sharp criticism from nationalists and many congressional leaders. They attacked Ongpin for being too concerned with preserving the Philippines' international credit status and negotiating a package that they derided as giving in to foreign lenders.

Proud, bordering on arrogant and impatient with those he perceived as intellectually inferior, Ongpin was known to be frustrated by what he saw as unwarranted criticisms from politicians that he considered ill-informed about the intricacies of international finance.

Ongpin, a graduate of the Harvard Business School, was known to talk down to colleagues and reporters who did not share his grasp of economics. In a sense, he became a victim of the competing philosophies that continue to tear at Aquino's government.

Since she came to power in February 1986, Aquino has been supported by conservative elements in the business community, represented by Ongpin, and left-leaning Filipino nationalists, represented by her first executive secretary and close adviser, Joker Arroyo. Those two factions shared the common goal of ousting president Ferdinand Marcos. Once Marcos was gone, their conflicting visions of how to rescue the country's ailing economy spilled into a highly personal public debate.

In particular, Ongpin and Arroyo had engaged in a bitter public exchange over economic policy, with Arroyo's faction advocating, in varying degrees, repudiation of the country's foreign debt, and Ongpin and conservative technocrats arguing that it was more important to preserve the country's standing with the World Bank, the International Monetary Fund and the private international lending community.

Following the August coup attempt, Arroyo was forced from office under mounting criticism from congressional, business, church and military leaders, who saw him as too leftist and incompetent as an administrator.

In return, however, Arroyo persuaded Aquino to fire his longtime nemesis, Ongpin. Moreover, Ongpin's departure was made public well before Arroyo's firing.

After he left the Cabinet, Ongpin set up an office as a private consultant in Makati, the city's business district.

Ongpin, who for more than a decade served as president and chief executive of Benguet Corp., the country's largest mining firm, was one of the influential group of Makati businessmen who first persuaded Aquino to challenge Marcos for the presidency following the assassination of her husband, former senator Benigno Aquino Jr.

In doing so, he broke with his brother, Roberto, who was minister of trade and industry under Marcos.

During that campaign, Ongpin emerged as one of Aquino's most influential economic advisers. He also played a key role during the February "people power" revolution that brought Aquino to power, negotiating between the Aquino camp and anti-Marcos group in the military led by then-defense minister Juan Ponce Enrile and armed forces chief of staff Gen. Fidel Ramos.

Aquino, in a statement, praised Ongpin and said his death "shocked me as it must all our countrymen.

"He fought the dictatorship during the martial-law years when few would do so. Jimmy was also a superb technocrat and organizer whose contribution to my presidential campaign was priceless."