Jobs will likely be the top issue as jet engine manufacturer Pratt & Whitney and the union for Machinists open contract talks this week.
Representatives of the union and the subsidiary of United Technologies Corp. would not discuss specific issues in negotiations set to start Thursday.
Union officials have said they may not recommend ratification of any contract without job commitments.
Pratt & Whitney says it employs about 32,000 workers worldwide, with about 15,000 in the United States. In Connecticut, it has about 9,000 employees, with about 3,000 covered by the contract.
The battle over jobs is not new. The jet engine maker lost a legal battle in 2010 to shut engine repair shops in East Hartford and Cheshire. It eventually won the right to cut the jobs in the contract negotiated that year.