Worldwide IT spending is set to hit $3.5tn (£2.2tn) in 2015, down 5.5 per cent from last year, according to analyst Gartner.
The figure differs significantly from its April forecast, which had spending set to grow 3.1 per cent in constant currency.
Enterprise software is the most promising category, with spend set to drop just 1.2 per cent in 2015.
The biggest drop – 7.2 per cent – is in the communications services sector, and not far behind is the devices market with a predicted 5.7 per cent decline.
Gartner said in the device market, mobile phones continue to lead the segment with growth in Apple phones, particularly in China, keeping overall spending consistent. But in general, smartphone unit growth will begin to flatten, and the analyst said the PC and tablet markets will “continue to weaken”.