The Commodity Futures Trading Commission has warned the nation's largest commodities exchange to stop persistent violations of federal regulations and begin inforcing its own trading rules.

If the exchange, the Chicago Board of Trade, does not act, the commission's Division of Trading and Markets " is prepared to recommend enforcement to a letter from Terry Claassen, director of the division, to the CBOT's new president, Robert K. Wilmouth.

CFTC sources said the tenor of the tart report on which the letter was based angered Commissioner Read P. Dunn Jr., who argued against the staff recommendations at a closed session Tuesday. Another commissioner, Robert L. Martin, is a past chairman of the exchange, whose members trade futures contracts in wheat, corn, soy-beans and a number of other commodities.

Sources said the commissioners finally agreed to permit the letter to be sent if it clearly stated that the recommendations were those of the staff, not the commissioners. The "compromise" reportedly resulted in the strongly worded enforcement threat, which stressed that the division would recommend such action.

The statement was issued following a routine rule enforcement review of the exchange by the commission. The CBOT was the next to the last of the nation's ten commodity exchanges to undergo such a review.

Among the deficiencies cited in Classen's six-page letter were infrequent disciplinary action against members who violate exchange rules and minimum sanctions imposed by the exchange on violators, inadequate or inaccurate records kept by the disciplinary committee, major weaknesses in its trading surveillance program, failure to update computer rec records to reflect corrections of errors in floor transactions and an ineffectual mechanism for handling customer complaints.

Classen noted that "the division has found generally the membership is concerned with protecting its self-interest at the expense of meeting its obligations for self-regulation. The reordering for self-regulation. The reordering of these priorities should be the CBOT's first stop toward achieving a continuous affirmative-action program."

The CFTC staff said the exchange must submit a plan for improving its market surveillance program and out-lined three major changes that it believes are needed. These include broadening the scope of the exchange's business conduct committee, encouraging staff independence and creativity, and giving the exchange's office of investigations and audits acaccess to all available data.

Wilmouth's response to the letter, issued late Wednesday, began, "Our rule enforcement program is the industry's very best, with by far the largest surveillance staff (37 professional personnel) and resources of over $1 million annually."

He continued, "When you are the best, you stay that way by listening carefully to all constructive comment, and we receive the CFTC's views in that spirit."

Wilmouth said the commission's criticisms "suffer somewhat from a misunderstanding of the (futures) markets, but we see those comments as a positive effort by the CFTC, our partner in public protection, to help us remain the very best."