(ShareCast News) - Manufacturing group Senior said strong currency headwinds hit its first half pre-tax profit, although revenue was boosted by favourable currency movements.The FTSE 250 company said its pre-tax profit for the first six months of the year edged 0.22% lower year-on-year to £45m, although it increased 5% on a constant currency basis.Revenue increased 8.5% to £434.5m, on the back of acquisitions and favourable currency movements, although it rose just 4% at constant currency."In response to these market headwinds, we are taking appropriate mitigating actions and anticipate some improvement in profitability in the second half of this year at current exchange rates," said group's chief executive David Squires."The group remains well positioned for the future as new Aerospace and Flexonics programmes and products enter production."Senior shares were down 1.62% to 273.20p at 0910 BST.