NEW YORK_A bankruptcy court judge on Monday allowed Delta Air Lines Inc. to enter new agreements, or hedges, to protect against sharp spikes in fuel prices and approved the rejection of a lease for a hangar at Dallas-Fort Worth International Airport. In approving the carrier's ability to enter the special agreements, Judge Prudence Carter Beatty cautioned the airline against speculating in non-fuel contracts. Many companies try to protect themselves from changes in interest rates, the value of the dollar and raw goods they rely heavily on with hedges. The hedges often come in the form of futures contracts purchased on exchanges like the New York Mercantile Exchange or the Chicago Board of Trade. Delta did not spell out exactly how it would hedge itself against rapid changes in fuel prices. Delta spokesman Dan Lewis could not immediately provide details about how the hedge process would work or when it would be implemented.