Engineering, consulting and project management giant AMEC said on track for double-digit jump in sales on the back of a strong order book and growing presence in the lucrative markets of the Middle East. International business has a strong presence in the North East with offices in Darlington, Gosforth, North Shields, Stockton, Wynyard plus Sellafield in Cumbria, where he had just secured two new long-term contract. Said business performance for the first three months of this year in line with expectations and the use of order "remains strong". The order book stood at £ 3.7bn at the end of March, up from £ 3.1bn last year, including a number of projects in Abu Dhabi. Closer to home, he was awarded a three-year framework agreement for specialist environmental consultancy support to the Sellafield nuclear site, including a 15-year design framework to support the development and improvement of new and existing equipment there, and for the decommissioning of the site. The number of staff worldwide surged to an average of 27,242 in the January to March period, up from 22,976 in the first quarter of 2011. Chief executive Samir Brikho said: "AMEC has performed in line with expectations in the first three months of this year. "We continue to see healthy demand for our services and investing in our end markets - supported by positive trends of the industry, particularly the oil and gas and mining sectors. We believe that it supports double-digit underlying earnings growth in 2012. Acquisitions made in 2011 as retrograde as additional acquisition opportunities and pipeline remains strong. ' The group announced on-market share buy-back program of £ 400m in February and is now sharing the purchase cost of £ 75 million. AMEC, which is headquartered in London, has annual revenues in excess of £ 3.3bn and operating in about 40 countries.