Omgeo, a promising start-up for international securities processing, has one year and two CEOs under its belt, but until last month it lacked Securities and Exchange Commission approval to open for business. Now the 500-employee joint venture of Depository Trust & Clearing Corp. and Thomson Financial is setting sail, with Adam Bryan, an eight-year Thomson veteran, at the helm. Shuttling between the company's main offices in Boston and New York, Bryan, 35, replaces Howard Edelstein, who founded Thomson Financial Electronic Settlements Group in 1993 and, with DTCC executive (and Omgeo chairman) Robert McGrail, laid the groundwork for Omgeo. Although Edelstein decided it was "time for a change," he plans to stay on as an adviser. He had expected to start operations in the first quarter, but SEC approval was slow in coming. All parties deny that the delay had anything to do with the musical chairs. In fact, Bryan, a former accountant from Australia, takes the SEC's deliberation in stride. "A deal this complicated needed the attention it got," he says. "Everyone is champing at the bit."