(Telecompaper) Gartner has lowered its forecast for worldwide device shipments this year, to a fall of 1 percent from estimated 1.5 percent in its previous forecast issued last quarter. The forecast covers combined shipments of PCs, tablets and mobile phones. The downgrade is a result of a slower replacement cycle for all devices, the market researcher said: "Users are extending the lifetime of their devices, or deciding not to replace their devices at all." Only mobile phone shipments are now expected to grow this year, by 1.4 percent. This is led by a 14 percent increase in smartphone shipments, which are growing fastest in emerging markets in Asia, such as India and Indonesia. The global PC market is expected to contract 7.3 percent this year to 291 million units and remain flat in 2016, hurt by the increase in prices due to currency fluctuations, which will slow business spending. The 'ultramobile' segment, which includes tablets and clamshell computers, is also on pace to contract in 2015, by 12 percent to an estimated 199 million units. Tablets will make up 192 million units, down 13 percent from 2014. Gartner said many tablet users are deciding not to replace their tablets. Its user survey conducted in June across six countries found that 44 percent of current tablet users are planning to substitute their tablets with a different device.