Dames & Moore, a Los Angeles-based environmental and engineering consultant, said it has agreed to acquire San Francisco-based O’Brien-Kreitzberg & Associates Inc., a construction management company, for an undisclosed amount of cash. . . . Gap Inc. said its Old Navy and Gap Warehouse stores voluntarily recalled baby overalls and “shortalls” sold in their stores because a small metal piece on the garments’ front clasp could become detached and pose a choking hazard. . . . Bell Atlantic Corp. is expected to announce today that it has picked tiny Silicon Valley start-up company DiviCom Inc. to make television converter boxes for delivering video services over telephone lines. . . . Incomnet Inc., a Woodland Hills-based telecommunications company, said it will buy back as many as 1 million shares of its stock on the open market, although a month ago it did not have even enough cash to pay its bills.