SAN FRANCISCO (AP) — A new report says personal computer sales slipped even further during the holiday shopping season, capping the worst annual decline in the PC industry's history.

The research firm Gartner Inc. estimates worldwide PC shipments for the three months ending in December dropped 7 percent from the same time in 2012. It marks the seventh consecutive quarter of decreasing PC sales.

For all of last year, PC sales plunged 10 percent. Shipments of desktop and laptop computers have never tumbled so dramatically. The numbers released Thursday show annual PC shipments have now backtracked to where they stood in 2009.

The PC slump is driven by the growing popularity of less expensive and more convenient mobile devices controlled by touch-screen technology instead of keyboards and computer mice.