(ShareCast News) - Rexam was looking at a year of positive sales growth on Thursday, but fluctuations in currency and lower prices saw earnings head south in the 12 months to 31 December.The FTSE 100 beverage can manufacturer saw sales increase by 2% over the year, to £3.93bn (from £3.83bn). Its underlying operating profit was down 3% to £404m, though the company's board said it remained flat at constant currency.Underlying earnings per share were up 5% to 39.1p.On a statutory basis, profit before tax was down to £250m, from £343m, with basic earnings per share down to 25.9p from 48.4p."I am pleased with our performance and progress as reported volumes grew 4% in difficult trading conditions. Underlying profit before tax is up 1% despite commoditisation of certain specialty cans in North America and higher energy costs in Brazil. We remained focused on our strategic priorities whilst supporting the anti-trust process for the Ball offer," said chief executive Graham Chipcase."We expect 2016 to present a tough trading environment but with continued volume growth. The expected premium benefit will be offset by pricing pressures in Europe and the savings from restructuring will be partially offset by cost headwinds. However, as ever, we continue to focus on tight cost management and the elements that we know we can control," he added.Ball Corporation had reached agreement with Rexam in February 2015 to acquire the entire share capital of Rexam, though the company resolved to continue as an independent company until the takeover was completed.The merger - worth £4.4bn - had hit some stumbling blocks at the EU regulator late last year, though both firms remained confident the deal would go ahead in a timely manner.During the year, the company's beverage can volumes were up 4%, or 2% excluding the acquisition of United Arab Can. While the company saw organic growth in line with, or ahead of, all regional markets, it was partially offset by currency fluctuations and lower pricing.Volumes were also affected by the commoditisation of a certain specialty can size in North America and higer energy costs in Brazil.Looking ahead, Chipcase said Rexam's combination with Ball would create a global packaging leader, driven by a desire to serve customers around innovation, manufacturing excellence, supply chain efficiency and sustainability."The proposed combination will also be able to respond to changes in the industry environment in a faster and more effective manner," he explained.The board declared a final dividend of 11.9p, taking the total dividend for the year to 17.7p per share, in line with 2014 and consistent with the Ball offer.