July 9 (Reuters) - Australia's Mining and Energy Union (MEU) said on Wednesday workers at Glencore's (GLEN.L), opens new tab underground coal mine in New South Wales began a 24-hour strike action in the afternoon, demanding wage hikes to match pay rates at a neighbouring site.

The union said its members voted for the midweek shifts to halt their operations at the Ulan underground mine for 24 hours, after 16 months of enterprise meetings failed to yield a satisfactory agreement.

Glencore's refusal to lift pay rates at Ulan Underground to match those at the neighbouring Ulan West mine sparked this wage disparity, the MEU said in its statement.

"We work for the same company, doing the same work just two kilometres down the road. We should be on the same base rate," MEU NSW South-West District Vice President said.

Glencore did not immediately respond to a Reuters request for comment.