SOFIA (Bulgaria), March 24 (SeeNews) – Bulgarian machine engineering company Hydraulic Elements & Systems [BUL:4HE] plans to raise its capital to 18.2 million levs ($13 million/million euro) from 3.0 million levs via a bonus share issue in a bid to boost its liquidity, an official of the company's parent, Stara Planina Hold, said on Monday.