Apple posts year-over-year sales gains while other PC vendors shrink.

The research firm expects PC shipments to grow by 6.5 percent in 2013.

Worldwide PC shipments declined by 0.1 percent during the second quarter, according to research firms Gartner and IDC.

PC prices could rise as a result of hard-drive supply shortages, IDC said.

HP's PC shipments also grew by 5.3 percent year-over-year in the quarter.

Gartner on Thursday lowered its growth forecast for worldwide PC shipments in 2011, joining a growing number of analysts who believe Apple's iPad 2 will bridge the remaining gap between laptops and tablets this year.

Worldwide PC shipments were slower than expected during the fourth quarter of 2010, hurt by competition from tablets and a slowdown in consumer spending, IDC said in a study released on Wednesday.

The continuing economic recovery and growing interest in mobile devices will drive PC shipment growth by 19.8 percent this year compared to 2009, IDC said on Tuesday.

Expecting the recession to worsen, IDC updated its PC shipment forecast on Thursday, saying shipments would decline further in 2009 before showing a gradual recovery in 2010.

The economic slowdown in the U.S. has led Gartner to revise its 2008 worldwide PC shipments forecast downward slightly but the analyst firm is still predicting a strong year, particularly in the mobility space.