President Alan Garcia reached for one of the several telephones that crowd a desk in his palace office recently and took a call from Peru's central bank chief. The country's reserves had risen another $100 million, Garcia was told. With an air of satisfaction -- and with two U.S. reporters present -- the Peruvian leader instructed the banker: "Don't let a single one go."

While other Latin American leaders groan under the burden of continued foreign-debt payments, Garcia is happily watching his country's monetary holdings grow. He has unilaterally limited debt payments to a fraction of Peru's export earnings, setting a precedent that he hopes neighboring states will adopt.

Peru's reserves have mounted from $894 million seven months ago, when the iconoclastic, 36-year-old Social Democrat took office, to about $1.5 billion now. The money is being hoarded to finance an ambitious reactivation program that Garcia likens, with a grin, to Reagan-brand, supply-side economics.

U.S. banks already have written off a large percentage of Peru's medium- and long-term debt, listing the loans as "value-impaired."

Last month, the International Monetary Fund gave Peru until April 14 to pay arrears of $72 million or else be declared "ineligible," a move that not only would block Peru from further IMF assistance, but possibly cut off funds from the World Bank and the Inter-American Development Bank. It also could complicate rescheduling of Peru's official debt.

Asked if he intended to meet the IMF deadline, Garcia teasingly told a gathering of foreign reporters here: "I'll tell you April 13."

Much can change between now and then on the Latin American debt problem, and this is what Garcia seems to be counting on. The drop in international oil prices has triggered new financial crises in Mexico and Venezuela, two of Latin America's largest debtors, and Garcia apparently is gambling that the immediate threat of nonpayment by these countries will push creditor banks and governments to adopt the Peruvian formula of linking debt payments to export earnings.

"It's not a matter of 10 or 15 or 20 percent," said Cesar Ferrari, Peru's vice minister of planning. "It's a matter of whether banks and governments accept the idea of payments tied to a percentage of exports. Once you accept that, the percentage is just a technical matter."

Peru actually has been paying more to foreign creditors than the 10 percent of export earnings that Garcia announced as a limit at his inauguration last July. The private sector here has continued to service its combined debt of $2 billion. Some state enterprises also have stayed current on payments, and the government has kept funds flowing to the World Bank, Inter-American Development Bank and Andean Fund. Peru's foreign debt is about $14 billion.

Garcia regards his battle with the IMF as politically necessary to steal the thunder from left-wing groups. At the same time, the Peruvian president has been careful so far not to break with the IMF nor its principal backer, the United States.