A college trustees' group and a coalition of foundations have annouced the creation of a center to improve management of the nation's 821,000 nonprofit organizations.

The National Center for Nonprofit Boards is being formed with $1.2 million from a variety of foundatons, including a four year grant of $885,000 from the W.K.Kellogg Foundation of Battle Creek, Mich.

The center is a joint project of the Association of Governing Boards of Universities & Colleges and the Independent Sector, a coalition of foundations, corporate philanthropies and voluntary associations.

More than 13 million people serve as board members of nonprofit organizations, which in 1984 spent $210 billion and had 6.5 million paid employes.

The center will provide consulting and technical services to boards in such fields as arts and culture, health and medicine, religion and social welfare.

It will produce publications, hold training conferences and serve as a clearinghouse of information.

Nancy R. Axelrod, who had been a vice president of AGB, was named executive director the center.

"With the cutbacks in social programs from all levels of government, boards of directors have become more crucial to the success of nonprofit organizations," said Robert L. Gale, president of AGB.