Raytheon and Aerojet Rocketdyne have entered into a strategic sourcing agreement, in which Aerojet will act as a principal and long-term supplier of Raytheon's legacy portfolio of propulsion systems and energetics products for key weapons programs, the companies announced Tuesday.

The partnership will help achieve the objectives of the Pentagon's Better Buying Power 3.0 initiative, which emphasizes greater efficiency in acquisitions, Raytheon Missile Systems President Dr. Taylor W. Lawrence said in a statement.

The agreement means the two companies will jointly pursue affordability initiatives through 2019.

"We are Raytheon's partner on some of the most important propulsion systems for our nation's warfigthers and national defense programs," Aerojet CEO and President Eileen Drake said in the statement. "This agreement expands our long-term relationship with Raytheon and is a direct result of our commitment to deliver quality products on schedule, while remaining firmly focused on affordability."

Among the projects the companies collaborate on is the throttling diver and attitude control system for the SM-3 Block IB missile system used by the U.S. Navy as part of the Aegis missile defense system.