Apple Inc. (NASDAQ:AAPL) Mac sales lags behind HP and Dell as shown by data from IDC and Gartner.

Apple's Mac sales decreased 11 per cent from its last year's third quarter to 1.9 million. Apple lagged behind HP and Dell as revealed by latest data from IDC.

IDC analyst Loren Loverde explained that Apple was more focused on tablets and other portable devices, hence the decline with Apple's Mac.

"Apple is a bit more focused on consumer and portable, and this quarter more of the growth was in commercial, so [it had] lower exposure to the segments that performed better this quarter," Mr Loverde told MarketWatch.

Meanwhile a report from AppleInsider compared the IDC data side by side with Gartner's report on PC sales.

According to the comparison, the estimates from both IDC and Gartner showed different figures, especially with the figures showing Apple's Mac sales.

IDC reported domestic Mac sales were off at 11.2 per cent year over year in the third quarter, while overall PC sales in the U.S. dipped at 0.2 per cent.

Gartner, on the other hand, reported that Apple's sales dipped just 2.3 per cent while PC market increased up to 3.5 per cent year over year. PC shipments worldwide totaled 81.6 million according to the IDC report - an 8 per cent decrease from 2013's earlier period. IDC said that they were expecting a decrease of 10 per cent due to the rapid growth of portable devices with tablets and smartphones heading the market.

"It's not as bad as we expected. This is not enough to radically change the outlook for this year and frankly, that applies to future years as well," Mr Loverde further explained.

Both reports showed that Lenovo was showing a year-over-year growth of 2 per cent but still was lagging behind Apple; Acer Group and Asus declining by more than 34 per cent.

Also, Both IDC and Gartner placed HP and Dell at number 1 and 2.

Gartner reported that HP's year over year growth was at 4.5 per cent jumping to a 26.9 market share.

Dell was up at 3.3 per cent and holding 21 per cent of the market.

Apple is at number three with a 13.4 per cent market share - down from 201when Apple had 14.2 per cent of the U.S. market.

Lenovo placed at number four from both of the reports.