(ShareCast News) - Aveva said it swung to a pre-tax loss in the first half of the year on the back of declining oil prices, adding that it hopes to reach definitive terms on the reverse takeover by Schneider Electric in December and complete the deal by mid-2016.For the six months to the end of September, the engineering software company made a pre-tax loss of £773,000 compared with a £14.17m profit in the same period last year amid challenging conditions in the oil and gas segment. Revenue fell to £82m from £85.9m.Chief executive Richard Longdon said: "We have been pleased with the resilient performance in the first half particularly with our recurring revenue growing on an underlying basis and a general strengthening of our pipeline.""We are confident in our technology leadership as well as the long-term structural growth drivers that underpin the markets we serve and, in the current fiscal year, we expect to achieve a result in line with the board's expectations."Aveva, which in July agreed to a £1.3bn reverse takeover by Schneider, said the deal will be transformational and the enlarged group will have an unmatched breadth of product offering."Both parties remain convinced of its merits and the key strategic and financial benefits that it will bring, including a more widely diversified product set, significant scale in North America, a generally more diverse regional and end market exposure, a significant presence amongst owner operator customers and enhanced shareholder returns," the company said.After a sizeable decline on Monday, shares in Aveva were up 1.2% to 2,030p by 0845 on Tuesday.