Hurt by consumers' continuing shift toward tablets and smartphones, PC shipments in the March quarter were down 4.4 percent compared with the same quarter in 2013, IDC said in a news release. IDC had previously expected a 5.3 percent dip for the quarter.

Gartner, a rival market research company, said in a news release that PC shipments in the March quarter fell 1.7 percent.

IDC and Gartner both said shipments in the first quarter got a bump as companies replaced their older PCs ahead of the end of the Windows XP operating system, which Microsoft stopped supporting on Tuesday.

"The transition to more mobile devices and usage modes is unlikely to stop, although the short-term impact on PC shipments may slow as tablet penetration rises," IDC said. "There is potential for PC shipments to stabilize, but not much opportunity for growth."

Gartner said total PC shipments in the first quarter were 76.6 million, while IDC said 73.4 million PC were shipped.

Intel, central to the PC industry, is due to post its first-quarter results on Tuesday. Analysts on average expect the chipmaker's revenue to have grown about 2 percent, according to Thomson Reuters I/B/E/S.

(Reporting by Noel Randewich; Editing by Jonathan Oatis)

Stocks treated in this article : Intel Corporation, Microsoft Corporation