Worldwide IT spending is projected to total $3.7 trillion in 2013, a 4.2 percent increase from 2012 spending of $3.6 trillion, according to the latest forecast by Gartner, Inc.

The 2013 outlook for IT spending growth in US dollars has been revised upward from 3.8 percent in the 3Q12 forecast.

Gartner analysts said much of this spending increase is the result from projected gains in the value of foreign currencies versus the dollar. When measured in constant dollars, 2013 spending growth is forecast to be 3.9 percent.

The Gartner Worldwide IT Spending Forecast is the leading indicator of major technology trends across the hardware, software, IT services and telecom markets.

"Uncertainties surrounding prospects for an upturn in global economic growth are the major retardants to IT growth," said Richard Gordon, managing vice president at Gartner. "This uncertainty has caused the pessimistic business and consumer sentiment throughout the world. However, much of this uncertainty is nearing resolution, and as it does, we look for accelerated spending growth in 2013 compared to 2012."

Worldwide enterprise software spending is forecast to total $296 billion in 2013, a 6.4 percent increase from 2012. This segment will be driven by key markets such as security, storage management and customer relationship management; however, beginning in 2014, markets aligned to Big Data and other information management initiatives, such as enterprise content management, data integration tools, and data quality tools will begin to see increased levels of investment.

The global telecom services market continues to be the largest IT spending market. Gartner analysts predict that growth will be predominately flat over the next several years as revenue from mobile data services compensates for the declines in total spending for both the fixed and mobile voice services markets. By 2016, Gartner forecasts that mobile data will represent 33 percent of the total telecom services market, up from 22 percent in 2012.

Gartner's IT spending forecast methodology relies heavily on rigorous analysis of the sales by thousands of vendors across the entire range of IT product and services. Gartner uses primary research techniques, complemented by secondary research sources, to build a comprehensive database of market size data upon which to base its forecast.