Apple's share of the U.S. computer market slipped again during the second quarter of 2014 despite a global trend towards growth in the PC marketplace after tablets like the iPad cannibalized sales.

According to IDC's preliminary results for the most recent June quarter, Apple continued to bleed marketshare in the U.S. PC industry, ending the three-month period as the only top-five PC vendor to have ceded ground year-to-year.

Update: Apple's officially released sales figures for the quarter state that the company's Mac sales actually increased by 18 percent globally as the overall PC industry remained stagnant. Apple's chief executive Tim Cook also stated the company had "achieved strong double digit Mac growth across many countries, including the U.S.," indicating that IDC and Gartner's estimates were incorrect and that Apple continues to outpace the overall conventional PC market, even when including Windows tablet shipments but not iPad sales.

For the quarter, Apple held 10 percent of the market on shipments of about 1.68 million Macs, down from 10.9 percent in the year ago period. The company's growth shrunk 1.7 percent year-over-year, leaving Apple in fourth place behind HP, Dell and Lenovo.

IDC data had HP leading the U.S. market with a 27.3 percent share on 4.6 million unit shipments, up 2.1 points from 2013. Second-place Dell also showed gains, moving from a 24.3 percent marketshare in 2013 to 25.7 percent in the three months ended June. Year-to-year growth for HP and Dell stood at 15.6 percent and 12.9 percent, respectively.

Lenovo's share of the market hit 11.5 percent on 1.9 million shipments, up from 9.8 percent last year. The Chinese company exhibited the highest growth out of the top-five OEMs, jumping 24.7 percent year-over-year. Rounding out the top-five, Toshiba managed to clear the one million units shipped milestone to claim 6.1 percent of the market. Growth was strong over the three-month period, adding up to a 20.6 percent change from last year.

Spurring the strong PC market performance were businesses looking to replace aging computers running Microsoft's Windows XP, which is no longer supported by the software giant, IDC says. On the consumer side, low-end computers like Chromebooks drove sales to help even out cannibalization from tablet devices.

"The better than expected results seem to arise from two places. One encouraging factor was a good intake of lower-end systems, including Chromebooks, which coincides with the recent slowing in tablet growth and perhaps signals the beginning of some stabilization on the consumer side," said Jay Chou, Senior Research Analyst at IDC's Worldwide PC Trackers. "In addition, a sizable number of PCs are still running Windows XP and the impetus to upgrade them continued to boost shipments in the second quarter."

Source: Gartner

A separate report from Gartner also put Apple as the fourth-place PC vendor in quarter two, with a 10.6 percent share of the market on shipments nearing 1.7 million. That figure is down from the same time last year, when Apple shipped about 1.68 million Macs to take an 11.5 percent marketshare. The research firm corroborated IDC's report by noting Apple as the only top-five PC maker to post negative growth year-over-year, dipping 1.3 percent from 2013.

Gartner's report also claims HP, Dell and Lenovo took the top-three spots, with share of 27.7 percent, 26 percent and 11.5 percent, respectively. Lenovo was seen as the largest driver of growth being up 20.3 percent year-to-year, though HP was close behind with 15.5 percent followed by Dell's 12.3 percent growth. Toshiba was named as the fifth-place finisher for the second quarter, netting 6.4 percent of the market on over 1 million unit shipments, up from 5.8 percent in 2013. The Japanese company exhibited second-highest growth at 18.5 percent.

There is a disparity between the two reports, however, as IDC found the U.S. PC market to have grown 6.9 percent year-over-year, while Gartner puts the number closer to 7.4 percent. Gartner points out that its data is limited to desk-based PCs, notebooks and Ultramobile Premium, the latter of which includes Windows 8 tablets. Lower-end devices like Chromebooks and other tablet were disregarded.