Formation of a corporation to help community group revitalize urban neighborhoods was announced today by the Ford Foundation and six private corporations.

The new corporation plans to identify about 100 local groups that have good track records but need an extra boost to be assured of long-term survival and help them become the "second generation" of community development organizations.

It is based on the premise that local groups working in deteriorating urban neighborhoods cannot prosper without a combination of private and government assistance.

Initial two-year funding for the organization, called the Local Initiatives Support Corp., is $9.95 million, half from the foundation and half from the corporations. These funds will be seed money to help local groups attract corporate and government funding.

Mitchell Sviridoff, who is taking leave from the Ford Foundation to be the first president of LISC, said a notunreasonable goal would be $20 from other sources for every $1 LISC puts out.

Ford Foundation president Franklin Thomas, former head of the successful Bedford-Stuyvesant effort in Brooklyn, noted that more community groups have failed than succeeded and said LISC is an effort to make the successful ones grow more quickly.

In most cases, LISC will make investments in the form of loans below market rate or loan guarantees, but it will also make modest grants --- not exceeding about $50,000 a year. It also will provide technical assistance to help the local leaders find financing and put together business deals.

Aetna Life and Casualty Foundation, Atlantic Richfield Foundation, Continental Illinois National Bank & Trust of Chicago, International Harvester, Levi Strauss and Prudential Insurance are the corporate backers of LISC.