Following the Federal Trade Commission’s approval early last week, GenCorp [GY] on Friday said it has completed its $550 million acquisition of the Rocketdyne business unit from United Technologies Corp. [UTX].

Rocketdyne will be combined with GenCorp’s existing rocket engine and missile propulsion business Aerojet to form Aerojet Rocketdyne, which will be headquartered in Sacramento, Calif. As part of the transaction GenCorp will acquire UTC’s 50 percent interest in the RD AMROSS joint venture following receipt of Russian regulatory approvals.

“Today is an exciting milestone in the history of GenCorp,” Scott Seymour, president and CEO of the company, said in a statement. “This landmark transaction signals the transformation of two rocket propulsion companies into one extraordinary opportunity for the future. The addition of Rocketdyne almost doubles the size of our company and provides additional growth opportunities as we build upon the complementary capabilities of each legacy company, including their talented people and innovative technologies.

Despite its concerns that the acquisition would reduce competition and innovation in the liquid divert and attitude controls niche of the rocket industry, the FTC blessed the deal after the Defense Department supported the combination for the sake of national security and the industrial base (Defense Daily, June 12). Meantime, the FTC is investigating whether space launch services provider United Launch Alliance (ULA) and RD AMROSS are maintaining an exclusivity agreement related the the supply of the RL-180 rocket engine that is hampering competition in the space launch market (Defense Daily, June 14). ULA is a joint venture between Lockheed Martin [LMT] and Boeing [BA].

The acquisition greatly expands Aerojet’s heavy lift rocket engine business and provides it with additional rocket boosters.