The global PC market should expand 4.4 percent in 2012, greatly exceeding 2011's anemic 0.5 percent gain, market researcher Gartner (NYSE: IT) predicted.

Globally, shipments of PCs may rise to 368 million units this year, compared with 2011's 358.2 million units, the researcher said.

Both U.S. leaders in the sector, Hewlett-Packard (NYSE: HPQ), the No. 1 manufacturer, and Dell (Nasdaq: DELL), No. 3 worldwide, reported anemic PC gains last year. China's Lenovo Group (Pink: LNVGY) took second place last year.

The forecast was published a day after Apple (Nasdaq: AAPL), introduced its latest version of the iPad, the bestselling entrant in the exploding tablet market.

Gartner and other researchers such as IHS (NYSE: IHS) estimate about 52 million tablets were shipped last year but the number should reach 320 million by 2015.

Besides Apple, which holds about 5 percent of the PC market but dominates the tablet sector, other PC makers with tablets shipping or in the pipeline include Sony, Lenovo, Samsung Electronics, Acer and Dell. HP, which withdrew from the sector last year, will re-enter, CEO Meg Whitman has promised.

Gartner analyst Ranjit Atwal said consumers will evaluate the task they have to perform before deciding on purchasing a PC or a tablet. The shift to the cloud, or Internet-based computing, may accelerate the shift away from the PC.

While PCs are ubiquitous in the developed world, Gartner predicted there will still be strong sales gains in the developing world, which is the target market of both HP and Dell.

Gartner shares rose 70 cents to $40.51 in afternoon trading.