One of the world's most important rocket companies, United Launch Alliance, may be sold later this year.

The potential sale has not been disclosed publicly, but three sources confirmed to Ars that potential buyers have been contacted about the opportunity. These sources said a deal is expected to be closed before the end of this year and that investment firm Morgan Stanley and consulting firm Bain & Company are managing the transaction.

The sale of United Launch Alliance, or ULA as it is known within the industry, would mark the end of an era that has lasted for nearly two decades. The company was officially formed in 2005 as part of a deal brokered by the US government, ensuring the military had access to both Atlas and Delta rockets to put national security satellites into space. To form ULA, Lockheed Martin and Boeing merged their launch businesses into a single company, each taking a 50 percent stake.

This union was profitable for both parent companies, as ULA held a monopoly on launching national security missions and, effectively, NASA science probes. In return for 100 percent mission success, ULA received large launch contracts and an approximately $1 billion annual subsidy from the US Department of Defense to maintain "launch readiness."

In response to a request for comment, Boeing released the following statement: "Consistent with our corporate practice, Boeing doesn’t comment on potential market rumors or speculation about financial activities."

Lockheed Martin issued a nearly identical response: "Consistent with our corporate practice, Lockheed Martin doesn’t comment on potential market rumors or speculation about financial activities.”

The emergence of SpaceX in the early 2010s with the increasingly reliable Falcon 9 rocket started to disrupt this profitable arrangement. SpaceX sold the Falcon 9 rocket at a substantial discount to ULA's Atlas V and Delta IV rockets. The company also successfully sued the US government to allow the Falcon 9 rocket to compete for national security missions, and SpaceX launched its first one in 2017.

In recent years, SpaceX has come to dominate United Launch Alliance in terms of cadence. By the end of 2022, the upstart was launching as many rockets each month as ULA launched during a calendar year. During the last four years, in fact, SpaceX has landed more rockets than ULA has launched during its existence.

However, ULA still holds a prominent place in the global launch industry, and there will likely be no shortage of suitors.