Beverage can producer Rexam said it was trading in line with expectations, even though a strong performance in Europe was offset by weakness in other markets.The FTSE 250 group said overall beverage can volumes increased 5% year-on-year in the three months to the end of March, boosted by a strong performance in Europe, which was driven by an increase in the volumes of energy drink cans.Rexam, which is being bought by US sector peer Ball Corp for £4.3bn, reported steady growth in the UK, Russia, Italy, India, Germany and Egypt but said it was hit challenging market conditions in the Middle East.A weaker market in the US, weighed on standard can volumes, while energy drinks drove specialty volumes higher.The South American market saw volumes decline towards the end of the period as weaker standard volumes weighed on overall volumes."Overall performance so far this year has been in line with our plans," said group chief executive Graham Chipchase."We continue to expect 2015 to present a tough trading environment, but, as ever, we will focus on tight cost management and the elements of our business that we know we can control."The London-listed company said aluminium premiums have fallen drastically and, at current rates, will translate in costs declining £10m to £15m in the current financial year, compared with the £30m the club had expected.Rexam shares were down 0.74% to 580.15p at 08:37 on Tuesday.