Hargreaves Services, which provides support services to the energy sector, took a tumble Wednesday after admitting it is discussing a possible merger with UK Coal.The coal miner confirmed yesterday it is "at a very early stage of investigating an approach it has received which could address the group's exposure to the volatile performance of its deep mines through a merger transaction". Speculation in the press forced Hargreaves to own up to being in "the early exploratory stages of cautiously reviewing a potential merger with UK Coal".It stressed discussions are at a very early stage and that there is no certainty any transaction will result. UK Coal has called the proposal "highly conditional".