NEW YORK (AP) _ E.F. Hutton Group Inc. announced a major reorganization today, including several top management changes, aimed at streamlining the company into two major divisions.

Hutton said it will focus on two ''strategic business groups,'' one covering services for individual investors and the other covering institutional and capital markets.

Spokesman Steven Nelson said that unlike some other brokerage firms that have expanded into such fields as real estate and credit cards, Hutton intended to remain focused on its current lines of business.

''We are not a financial services conglomerate. Our mission is narrower,'' the company said in a news release.

E.F. Hutton & Co., Hutton's stock brokerage subsidiary, was shaken in May by its guilty plea to 2,000 counts of mail and wire fraud involving a scheme to earn extra interest by deliberately overdrafting its bank accounts. Nelson said the company had intended to reorganize itself before that.

Robert Rittereiser, who has been president and chief operating officer of Hutton since last summer, will take on the additional position of president of the E.F. Hutton & Co. subsidiary, the company said.

Rittereiser was hired in June from Merrill Lynch & Co., where he was an executive vice president.

The reorganization was based on a plan developed by Rittereiser at the request of Robert Fomon, Hutton's chairman and chief executive, Nelson said. Nelson said Fomon discussed the plan with Rittereiser and had final say over all its aspects.

Scott Pierce, formerly president of E.F. Hutton & Co., will become vice chairman of the parent company, where he will ''have overall management responsibilities and assume additional responsibilities,'' the company said.

Hutton spokesman Robert M. Sharkey said the company would ''shortly'' announce the appointment of a new chief financial officer and a new general counsel.

Hutton announced in September that Thomas W. Rae, the general counsel, was taking an early retirement and would enter private law practice once a replacement was in place.

Hutton also announced in September that Thomas Lynch was relinquishing his duties as chief financial officer, vice chairman and corporate secretary. Sharkey said today that Lynch had been reassigned within the company but kept his spot on the board of directors.

Jerome H. Miller, formerly executive vice president of Hutton's equity division, was promoted to senior executive vice president and will head the newly formed individual investment services group, Hutton announced today.

Richard S. Locke, formerly executive vice president overseeing corporate and public finance and fixed-income trading, retains responsibility for those areas and has been promoted to senior executive vice president and is the senior executive in the newly formed institutional and capital markets group, Hutton said.

Both Miller and Locke will report to Rittereiser.