The Treasury will halt sales of U.S. Savings Bonds at midnight tonight and cancel its Treasury bill auction Monday because Congress has failed to approve an increase in the national debt limit, now at $2.32 trillion . . . Beverly Hills-based Great Western Financial Corp., which is seeking to concentrate on core business, sold two wholly owned subsidiaries, Great Western Leasing and Great Western Credit, to a Citicorp affiliate . . . An investment group seeking control of San Francisco-based Di Giorgio Corp. has extended its $28-a-share offer until July 21 and says it may increase the bid if it can look at internal company documents . . . Jamie Securities of New York said it has lowered its stake in KaiserTech Ltd. to 4.81% of the common shares outstanding.