WASHINGTON — In its quest to modernize the U.S. Air Force’s stockpile of intercontinental ballistic missiles, Northrop Grumman has partnered with Bechtel and Kratos Defense and Security Solutions, the company announced Tuesday.

The two companies are the latest addition to Northrop Grumman’s nationwide team devoted to replace the Minuteman III with next-generation missiles, as the company announced in September its collaboration with hundreds of companies across the defense, construction and engineering industries.

“Together, this expanded team has the capacity, capability and credentials needed to deliver – on time – a safe, secure, reliable and effective nuclear deterrent capability for the U.S. and its allies for the next 50 years,” said Greg Manuel, vice president of Northrop Grumman’s Ground Based Strategic Deterrent team.

Bechtel, an engineering, construction and project management company, will provide construction and integration, and launch system design, according to the announcement. Kratos Defense and Security Solutions, which specializes in unmanned systems and missile defense, will provide vehicle transporters.

Northrop Grumman is the de facto winner of the $85 billion contract, expected to be awarded in the fourth quarter of 2020, after Boeing declined to bid on the program by the Dec. 13 deadline. Boeing claimed Northrop Grumman had an advantage to offer the lowest-cost system, thanks in part to its acquisition of one of only two U.S. solid-fuel rocket motor manufacturers. Boeing proposed, unsuccessfully, that the Air Force demand a joint team be formed between the two companies.

The Air Force said it will proceed with “an aggressive and effective sole-source negotiation,” according to a statement released in December.

Members of Congress have expressed concern over a sole-source contract. House Armed Services Committee Rep. Adam Smith, D-Wash., suggested the Air Force has shown bias toward Northrop Grumman and questioned the need for the program.

“It is very troubling that it’s going to be a sole source contract,” Smith said at an event sponsored by Ploughshares Fund in October. “The thing to do would be to address the concerns that Boeing raised about the procurement process. Because, if Boeing is to be believed, they didn’t say ‘We just can’t do this anymore.’ They said the process wasn’t fair.”

In August, Northrop Grumman broke ground near Hill Air Force Base on a new facility that will serve as the headquarters for the company’s workforce, which will add thousands of jobs in the state of Utah, according to the release.