Scott Martin

USA TODAY

SAN FRANCISCO -- The PC market continued its downward spiral in 2013, logging its worst decline since the dawn of the personal computer, as consumers continue to snap up mobile gadgets at a feverish pace.

Worldwide PC shipments slumped 6.9% in the fourth quarter of 2013 compared with a year ago, according to research firm Gartner. The downdraft marks the seventh-consecutive quarterly decline in PC shipments. Hit hard by consumer preferences for smartphones and tablets, full-year PC units plummeted 10% compared with 2012.

"Strong growth in tablets continued to negatively impact PC growth in emerging markets," says Gartner analyst Mikako Kitagawa.

PC market declines underscore the growing pressures facing Microsoft to reinvent itself in an era dominated by mobile devices, an area in which its Windows software remains a perennial laggard.

Despite declines, Lenovo continues to grow. The Beijing-based company shipped 14.9 million units worldwide in the quarter, compared with 14 million a year ago, growing 6.6% year over year.

Hewlett-Packard didn't. The Palo Alto, Calif.-based PC maker's fourth-quarter shipments fell 7.2%, to 13.6 million units from 14.6 million a year ago.

PC maker Dell, which last year completed a leveraged buyout in a bid to go private, grew 6.2% in the quarter on shipments of 9.8 million, compared with 9.2 million in the year prior.

Apple was the biggest PC gainer in the U.S. The Mac maker grew 28.5% year over year, on fourth-quarter shipments of 2.2 million units, compared with 1.7 million in the year ago period.

Still, Gartner says it believes that PC markets in the U.S. and other regions have "bottomed out."