An investor looking for a place to put $1,000 in 1984 might not have thought of the Manila stock market, but if he had taken the plunge he would have found the average return on his investment at the end of last year to be $14,880, according to a new study.

On U.S. markets, the average return for the four years - the value of the stocks themselves plus dividends - would have been a tame $1,910.Manila showed the best average return worldwide in a study by the International Finance Corporation, which looked at stock markets in both major money centers and 31 Third World countries.

The corporation, owned by 133 governments, is the agency of the World Bank that lends to private industry.

The corporation's Charles O. Seth-ness said the large gain in the value of stocks on the stocks on the Manila exchange "was all due to the instability until (former President Ferdinand) Marcos left."

The Manila exchange jogged along through 1985 without much change, despite the violent political campaign that led to the victory of President Corazon Aquino but took off after Marcos flew to exile in Hawaii in February 1986.

By June 1987, the average return on stocks had reached a level nearly 16 times the level of 1985.

There was a sharp drop in Manila when markets worldwide crashed in October 1987. But, by the end of last year, total returns were back almost to their peak.