BATH – Bath Iron Works’ plan to replace some union custodial jobs with a cleaning services subcontractor has been put on hold for three months while talks continue between the Navy shipbuilder and its largest union.

The Machinists Union threatened to picket the christening of the Navy ship Farragut later this month if management didn’t pull back its proposal. The plan called for replacing 24 union custodial and maintenance workers.

Company President Dugan Shipway announced the plan last week as part of ongoing efforts to make the shipyard more efficient.

But he issued a statement to workers Wednesday explaining that the plan was being shelved for the time being while discussions continue.

The company and union officials will explore alternatives to using a subcontractor from Massachusetts for cleaning office space.

If the discussions fail to yield savings, then the company will proceed with its plan and the union reserves the right to contest it, Shipway said.

Bath Iron Works is facing a declining workload even under the best-case scenario as the current Arleigh Burke-class destroyer program winds down and the shipyard makes a transition to construction of the next-generation “stealth” destroyer.

But the outlook worsened as the Navy scaled back the DD(X) destroyer program and proposed to have one shipyard build the new ship instead of divvying up the work between Bath Iron Works and Northrop Grumman’s Ingalls shipyard in Mississippi.

The latest Navy proposal calls for letting both shipyards build one ship to see who’s best and then decide whether to divvy up the work or let one shipyard build the remainder.

Assistant Navy Secretary John Young said in May that he wanted to “put these two yards in a competitive death grip” to force them to become more competitive and to produce a design for the stealth destroyer that’s more affordable for the Navy.