Specialist recruitment firm Hydrogen reported a slight rise in first half profit thanks to robust performances from its international operations and its Technical & Scientific practices but it expects the overall economic backdrop to remain challenging.Net fee income rose to £15.6m in the six months to the end of June from £15.1m the year before. Net fee income from permanent placements climbed to £7.6m from £7m while contract NFI was broadly unchanged at £8m.Pre-tax profit rose to £1.9m during the period compared to £1.8m a year ago while basic EPS increased to 6.13p from 6.01p.Executive chairman Ian Temple said: "Strong performances from our international operations and our Technical & Scientific practices have enabled us to deliver NFI and profit growth in the first half of 2012 despite difficult market conditions."He added that the group continues to trade in line with the board's expectations and there has been no adverse impact on recruitment activity in the UK because of the Olympic Games."We remains on target to meet our expectations for the year as a whole and we expect the overall economic backdrop to remain challenging but will continue to develop our practice-led strategy, investing in markets where we see potential for growth," he added.The interim dividend has been increased by 7% to 1.5p.CJ