The Supreme Court yesterday refused to intervene in a turf dispute between the Securities and Exchange Commission and the Commodity Futures Trading Commission.

The decision will force the lame-duck session of Congress to determine which of the agencies will regulate some new kinds of investments that are related to both securities and commodity futures contracts.

The high court declined to review a ruling by the Seventh Circuit Court of Appeals in Chicago, which said the SEC exceeded its authority when it permitted the Chicago Board Options Exchange to trade in options on government-insured home mortgages.

The SEC decision was challenged by the Chicago Board of Trade, which already trades futures contracts in home mortgages and wants to protect its monopoly. The lower courts ruled that mortgage options can only be regulated by the CFTC.

Both mortgage futures and mortgage options can be used to speculate on whether interest rates will go up or down and to protect lenders and borrowers against unfavorable changes in mortgage rates.

SEC Chairman John S.R. Shad and CFTC chief Philip McBride Johnson last year negotiated an end to the long-running turf fight and asked Congress to ratify their plan for dividing the jurisdiction. The agreement is part of a CFTC reauthorization bill that is pending in Congress.

The Shad-Johnson agreement gives the SEC authority to permit trading in some nonstock options and, in effect, would overrule the Seventh Circuit Court decision.

Yesterday's decision is expected to put new pressure on Congress to ratify the SEC-CFTC jurisdiction agreement, which otherwise would have been a low priority during the three-week session of the legislature.