Chicago ? United Airlines and its machinists’ union announced an agreement in principle on a contract in federal bankruptcy court Tuesday, narrowly heading off the need for a judge’s ruling that could have triggered a strike.

A formal contract agreement is to be presented in federal bankruptcy court June 17. Judge Eugene Wedoff gave the two sides until then to work out remaining details.

The agreement in principle came just hours after United’s mechanics ratified a five-year contract, giving the No. 2 U.S. airline a pair of crucial labor victories that it needed to avoid an employee walkout and strengthen its bid to come out of bankruptcy.

The tentative deal with the International Association of Machinists and Aerospace Workers, representing 20,000 baggage handlers, customer service representatives and other ground workers, was disclosed in court with Wedoff poised to rule on United’s request to break the contract. The IAM had warned it would shut down the carrier with a walkout if that happened.

The company asked for $175 million in yearly concessions from the IAM, its largest union, to complete a companywide package of $700 million in annual labor savings. When complete, the tentative pact must still be ratified by the IAM’s membership.

The mechanics agreed by a 59 percent to 41 percent vote to ratify a contract containing $96 million in annual concessions, including 3.9 percent pay cuts and reduced benefits.

The 7,000 mechanics, like other United employee groups, have expressed anger about a second round of reductions during the airline’s 2 1/2-year-old bankruptcy but knew they ran the risk of putting United out of business with a vote rejection and strike.