Employees of electricity distribution company CEZ Bulgaria, which services the western part of the country and capital Sofia, went on effective strike on April 10, labour unions said, as quoted by Bulgarian news agency BTA.

A total of 77 per cent of the company's employees were on strike after failing to reach an agreement on wage hikes, BTA quoted Denko Roidev, chairperson of the strike committee, as saying. CEZ employs 4600 people at its three power distribution subsidiaries, according to information posted on its website.

CEZ said it would not allow blackouts and had prepared contingency plans for the duration of the strike. Labour unions have said earlier that their strike would have little impact on end-consumers.

The unions are demanding a 25 per cent wage hike, applied retro-actively from February 1 2008, with CEZ offering and average 19.9 per cent increase and a 20 per cent increase of overtime wages. Earlier this week, the company sweetened its offer to 23.4 per cent, which the labour union once again rejected.

The unions are also demanding that the company cancels the staff cuts planned for May. On March 14, CEZ regional manager for Bulgaria Luboš Pavlas said that 400 employees would be made redundant.