General Electric, the listed, Connecticut-based conglomerate, walked away from its deal to buy two Abbott Laboratories diagnostic units because it did not want to face additional regulatory problems, according to industry sources. GE and Abbott were discussing the transfer of certain units and final terms this spring when Abbott received FDA notice of a problem at Abbott production plant in Texas, according to a person familiar with GE’s strategy but not involved in the deal. The warning letter from the FDA said the agency was not satisfied with the progress by Abbott in correcting manufacturing shortcomings that FDA inspectors had identified in previous months.