Despite revealing solid growth in 2014, shares in Northbridge Industrial Services took a hit after the equipment supply group warned first-half profits would be lower than last year's.Northbridge said current volumes and margins in its oil tool rental business were even worse than expected and that larger projects carried out by its Crestchic loadbank business in the Middle East and Far East, which are connected to the oil and gas sector, were likely to be subject to the usual delays and postponements."Underlying demand for our goods and service will take some time to stabilise and, as current contracts unwind, replacement contracts are likely to be harder to secure," it added.Management were encouraged by the level of enquiries in both the oil tool rental business and Crestchic businesses, although revenue visibility at this stage was poor.Power reliability and power projects were expected to fare better, particularly in economies that were enjoying growth again, with growth supported by the lower price of energy. "Although it is too early yet to give an update on full year expectations, management expects that results for the six months to 30 June 2015 will be less than those achieved in the comparative period to 30 June 2014," the statement said.Results for 2014 showed revenue up 19.4% to £44.9m and pre-exceptional profit before tax up 16.5% to £7.0m.Basic earnings per share before exceptional items were up 13% to 32.5p.Chief executive Eric Hook said: "Whilst revenue visibility is noticeably reduced in our rental activities at present we continue to be confident in the group's longer term prospects and remain committed to the group's stated successful strategy and objectives."