The National Labor Relations Board has ended its years-long legal dispute with Elon Musk's SpaceX, according to correspondence from the agency. The Board indicated it will avoid future litigation against the company, citing a lack of jurisdiction.

Two years ago, the labor board filed a lawsuit against the aerospace company, alleging it had fired eight engineers for participating in an open letter criticizing Musk. The Board has now stated it will dismiss the case.

In a letter to the lawyers representing the former employees, the NLRB referenced a recent opinion from another agency—the National Mediation Board—stating that SpaceX engineers fall under that agency's jurisdiction, not the labor board's.

Danielle Pierce, a regional director for the NLRB, wrote in the letter: "Consequently, the National Labor Relations Board lacks jurisdiction over this employer, and I am therefore dismissing your charge."

Last August, a U.S. appeals court sided with SpaceX and two other companies, agreeing that the NLRB's internal structure might be unlawful. The ruling prevented the agency from pursuing cases against those three companies.

The National Mediation Board oversees railway and airline companies, such as American Airlines Group, while the National Labor Relations Board regulates most other private-sector employers, including manufacturing companies like Boeing.

Under federal law, employees under the NLRB's jurisdiction have the right to engage in various collective activities aimed at improving working conditions, regardless of union membership. Employees under the NMB's jurisdiction are covered by a different set of laws that lack equivalent protections.