GenCorp Inc. [GY] said Tuesday evening that it is preparing to sell its Liquid Divert and Attitude Controls (LDACS) businesses to comply with federal antitrust requirements as part of the company’s pending acquisition of United Technologies Corp.’s [UTX] rocket engine business.

GenCorp said that it has received a modification to the request for additional information from the Federal Trade Commission (FTC) related to its acquisition of Rocketdyne from UTC’s Pratt & Whitney division. The FTC’s investigation of the deal is limited to the LDACS businesses and excludes large and medium liquid rocket engines for launch vehicles and spacecraft.

GenCorp in July announced it had agreed to acquire Rocketdyne from UTC for $550 million, a deal that would significantly expand its heavy-lift engine business (Defense Daily, July 24). The deal, which GenCorp still expects to complete in the first half of 2013, is expected to nearly double the size of the company.

GenCorp’s Aerojet propulsion and motors business is known for its tactical rocket motors and propulsion products, although it manufactures or modifies several engines.