Attorneys for rail lines seeking to buy the bankrupt Milwaukee Road are to argue their cases Thursday before U.S. District Judge Thomas R. McMillen, who is overseeing the bankruptcy reorganization of Milwaukee Road. McMillen surprised officials of Chicago & North Western Transportation Co. by announcing Monday that he favors selling the company to Soo Line Railroad. C&NW; had been considered the front-runner in the long and heated bidding war for Milwaukee Road because its $782-million offer exceeds Soo Line's $571-million bid by $211 million. The benefactor of that $211-million difference would be shareholders of Chicago Milwaukee Corp., the parent company of Milwaukee Road. McMillen said he would issue a decision "no later than Friday" on which company would buy the 3,100-mile, Chicago-based Milwaukee Road.