NORTHWEST AIRLINES TODAY ANNOUNCED AN ALLIANCE WITH CONTINENTAL AIRLINES. THE MOVE WILL BOOST REVENUES AND SOLIDIFY THE AIRLINE'S POSITION IN THE INDUSTRY. BUT IT MAY NOT REDUCE FARES. MINNESOTA PUBLIC RADIO'S BILL CATLIN REPORTS. THE ANNOUNCEMENT CAME AFTER WHAT APPEARED TO BE FRACTIOUS, ON-AGAIN OFF-AGAIN DISCUSSIONS BETWEEN CONTINENTAL, NORTHWEST AND THE NORTHWEST PILOTS UNION ... WHICH HAS VETO AUTHORITY OVER THE DEAL. TWO WEEKS AGO, THE PILOTS UNION DECIDED THE STRATEGIC ARRANGEMENT WITH CONTINETAL COULD BE PROFITABLE FOR NORTHWEST. HOWEVER, DELTA AIRLINES APPARANTLY LIKED THE IDEA AS WELL. C