International Finance Corp.

The International Finance Corp., the private-sector investment affiliate of the World Bank, said Thursday it is making its largest investment ever in a $300 million project in Chile.

The 30-year-old corporation will buy a 7.7 percent interest at a cost of $5 million in Signal Methanol Inc., which will make methanol, or methyl alcohol, from natural gas in an installation at Cabo Negro, the southernmost tip of the country.

Most of the product is to be sold in the United States, providing Chile with $62 million a year in foreign exchange.

The International Finance Corp. also will make loans of $50 million to the new project.

The corporation is owned by 128 countries, with the U.S. government owning the biggest block of shares.

Terms of the loans were not revealed. Export-Import Bank

The Export-Import Bank, the U.S. agency that makes loans to importers of U.S. products, said last week it has reduced interest rates on all loans, except for commercial jet aircraft, by 1.05 percent.

The rates were reduced to the lowest permitted under an international agreement between 22 members of the Organization for Economic Cooperation and Development.

The minimum rates are reviewed twice annually and are based on a weighted average interest rate on government bonds denominated in the U.S. dollar, German mark, British pound, French franc and Japanese yen.

The bank said that interest rates on loans to relatively poor countries will drop to 8.80 percent from 9.85 percent, while those to rich countries will decrease to 10.95 percent or 11.20 percent, depending on the duration of the loan.

Interest on loans to "intermediate" countries, which account for the largest portion of the bank's lending, will drop to 9.65 percent for two- to five-year credits and 10.15 for credits over five years.