(Telecompaper) Mobile operators need to prepare for the first contraction in the industry's history, according to new forecasts from Ovum. The market researcher expects global mobile service revenues to decline for the first time in 2018, as customer growth slows and ARPUs decline. Over the period 2012-2018, global mobile connections are expected to show a CAGR of 4 percent, to reach 8.1 billion at the end of the period. Annual mobile service revenues will rise over the same period from USD 968 billion to USD 1.1 trillion. The decline will set in the last year, with revenues falling by 1 percent or USD 7.8 billion in 2018. While some operators may be able to hold off the decline by merging or acquiring rivals, they will also need to rethink their business models and work harder on innovation, Ovum. Those in Western Europe will find it particularly challenging, with revenues expected to show a CAGR 1.48 percent over the forecast period. Several other developed markets will see year-on-year revenue declines in 2018, including the US, which will begin to show signs of its maturity. Much of the global revenue decline is due to falling ARPU, which Ovum predicts will show a CAGR of minus 2.7 percent between 2012 and 2018. Despite the global trend, some growth opportunities will still exist, particularly in Africa, where revenues are expected to grow at a CAGR of 4.2 percent throughout the forecast, and in select markets in Asia-Pacific and Latin America.