The U.S. economy grew at a solid 3.9% annual rate in the July-September period, giving the country its strongest six months of growth in more than a decade. The Commerce Department reported on Tuesday, the third quarter growth rate climbed from an initial estimate of 3.5% because of greater spending by consumers and businesses. The figure followed a 4.6% surge in the spring, which resulted in the biggest consecutive quarters of growth since 2003. Analysts believe growth could slow to around 2.5% in the current quarter but then accelerate again in 2015. They expect growth of around 3%, representing a sustained acceleration in activity six years after the Great Recession. Economists are looking for a solid performance in the final three months of this year but slightly below the third quarter pace. For the entire year, growth is forecast at a modest 2.2%, matching the modest increase of 2013.