James O. Roberson, for four years head of the Maryland Department of Economic and Community Development, yesterday announced he is resigning to take a high-salaried job running the Louisville (Ky.) area Chamber of Commerce.

Roberson's unexpected departure is the sixth from the 13-member cabinet of Gov. Harry Hughes since Hughes' reelection to a second term last November.

Hughes has had to find new secretaries of prisons, natural resources, health, human resources and general services. In addition, Hughes recently appointed the head of a new department of employment and training.

Hughes staffers said the governor learned only yesterday morning of Roberson's decision to leave at the end of this month, and therefore has not begun to search for a successor.

According to officials in the economic development department, Roberson, 48, decided to leave Maryland after the Louisville chamber offered to pay him a salary "well above" the $62,000 he makes in Maryland. One official estimated the chamber salary at near $100,000.

His decision to leave, they said, was not prompted by recent criticisms of the department or of the state's economic development efforts.

Several months ago, a legislative auditor found "major problems" in the management of the department, including garbled accounts that left officials unable to account for millions of dollars.

Some members of the legislature, irate at what they said was a mess in the department that was established to promote Maryland and attract new business, wanted to dock Roberson's pay. But Hughes came to Roberson's defense and the department has been working on clearing up its financial affairs.

During the same time, several major Maryland businessmen, primarily those heading utility companies, have charged that the state has cultivated an "anti-business climate." Both Roberson and Hughes have strongly denied that contention.