Arguing that the industries upon which New York City has depended for its economic well-being have been losing ground and are unlikely to generate many new jobs in future, a new study suggests that New York's longtime approach to economic development is obsolete and must be reconceived.

The study, financed by the Rockefeller Foundation and written by a nonprofit group called the Center for an Urban Future, says the city should abandon the "doomed strategy" of favoring a few industries like finance ? an approach the study says has left the city increasingly vulnerable to economic shifts.

City resources should go instead to improving the climate for small businesses and entrepreneurs, tapping the immigrant population as well as academic and research institutions, and improving basic services so the middle class will not leave the city, according to the study, to be released today.

"Start small," the report urges. Large firms are decentralizing operations and adding new jobs elsewhere, and New York's future growth will depend on "whether it can restore its entrepreneurial vitality and create a better environment for smaller firms to grow and prosper."

The recommendations run counter to the city's practice of using tax abatements and real estate development subsidies to keep big companies in New York. That tactic became common in the 1990's as competition among the city, its suburbs and other places intensified.

Several economists and others who have seen the report said the recommendations were sound. Some said they also seemed consistent with some recent moves by the administration of Mayor Michael R. Bloomberg toward delineating a clear strategy and diversifying the economy.

"The city has never had a clear economic development strategy," said Kathryn S. Wylde, president of the Partnership for New York City, a business group. "The city's strategy has been real-estate-driven and has been reactive to the threat of corporate move-outs and job losses rather than job creation."