A controversial program that for five years provided Harvard professors with low-interest loans for houses in Cambridge had little effect on the city's housing market, a University official said in a letter presented to the city council last night.

Contrary to city officials' expectations, residences bought through the Cambridge Option Plan (COP) comprised only 1.26 percent of the total sales during the period it was in operation, said a letter from Robin Schmidt, vice-president for government and community affairs.

Schmidt added that the average price of houses purchased under COP was $143,000, a figure "significantly above the level which would seriously impinge on the low and moderate income market."

Low-to-moderate income housing is traditionally tight in Cambridge.