Steve's lee cream, a popular late-night stop for Harvard students, has been sold to a New York-based conglomctrate for an undisclosed amount of cash, a spokesman for Steve's said yesterday.

Integrated Resources, which took over operation of the 18-store chain late last week, announced plans to open 500 new outlets over a period of four years.

Joey Crugnale, who had operated the chain in partnership with his brother Nino and James Miller, indicated that franchising headaches had led to the sale.

"It was just too big for us," he said yesterday. "We couldn't handle it Twenty people were calling for franchises each day."

Fourteen stores are currently franchised to other owners, including the one in Harvard Square. The chain has locations in cities as far away as Boulder. Colorado and Washington, D.C.

A spokesman for the purchaser said that further expansion would not change the way that Steve's operates Ice cream will continue to be manufactured on the premises at each location, he explained.

Despite the Crugnales' problems with the growing renown of Steve's, the suddenness of the sale came as a surprise to some employees Fred Baldinelli, the manager of the original Steve's in Somerville, said that he had expected the sale of the chain, but was surprised that it came this soon.

Customers, however, were not concerned with the particulars of the sale, but with the continued quality of the ice cream. When asked if quality would decline. Crugnale responded. "That's foolish. Each store makes its own ice cream, and the new owners are not going to change that."

Jean Laughlin, manager of the Harvard Square location, agreed. "It's just new management and [Steve's] will continue to be a franchise operation."