By Noel Randewich SAN FRANCISCO (Reuters) – Nvidia Corp gave a revenue forecast for the current quarter that was shy of Wall Street’s expectations as the graphics chipmaker faces tough competition in tablets and a slow personal computer market. With the personal computer industry losing steam, Nvidia has expanded its graphics chips into tablets and is working on smartphone chips, but it is meeting stiff competition from Qualcomm Inc and other rivals, and some analysts said the chipmaker should exit those markets. In the third quarter, sales from Nvidia’s Tegra mobile chips fell 54 percent and sales from its PC graphics chips, which accounts for the majority of the company’s total revenue, declined 2 percent. Nvidia expects its mobile chip business, called Tegra, to remain flat this year as it focuses on integrating Long Term Evolution (LTE) features on upcoming components, making them compatible with high-end carrier networks and more attractive to smartphone makers.