LONDON, Jan 12 (Reuters) - Workers at Britain's Atomic Weapons Establishment (AWE), which provides and maintains the country's nuclear warheads, will stage two 48-hour strikes in coming weeks in a dispute over their pensions, the Unite labour union said on Thursday.
AWE, which is jointly owned by U.S. firms Jacobs Engineering Group and Lockheed Martin and British support services group Serco, supports Trident, Britain's submarine-based nuclear deterrent programme, under contract to the Ministry of Defence.
Unite said 600 of its members who are AWE employees at the two main facilities at Aldermaston and Burghfield in Berkshire, southeast England, would walk out for 48 hours, starting on Jan. 18 and on Jan. 30.
AWE has about 4,500 staff and 4,500 contractors in total working across all its sites.
"Unite members feel 'deeply betrayed' as promises made a quarter of a century ago guaranteeing their pensions, when they were transferred from the Ministry of Defence to the private sector, have been broken," the union said in a statement.
A spokeswoman for AWE said the company would respond later.
Unite said AWE management planned to close a defined benefit pension scheme on Jan. 31 and replace it with a defined contribution one in which final retirement income is not guaranteed.
"The most just course of action would be for the pension scheme to be taken back by the MoD (Ministry of Defence)," said Unite regional officer Bob Middleton.
A spokesman for the MoD had no immediate comment.
The union said 92 percent of its members at AWE, who include managers and manual workers, had voted for strike action. (Reporting by Estelle Shirbon; editing by Stephen Addison)