Apple’s iTunes has reasserted its top position in the US online movie market in the first half of 2010, according to a new research from industry research and consulting company IHS.

The new IHS Screen Digest Media Research reveals that iTunes’ share of US consumer spending for movie electronic sell-through (EST) and Internet video on demand (iVOD) was up by 65.8% from 64.9 % for the same period in 2010.

According to the data, iTunes experienced the largest revenue increase growth among all online movie providers during the first half.

The research firm said much of iTunes’ success is led by the rising usage of Apple’s AirPlay technology, that allows wireless video streaming to consumer electronic devices including televisions.

In addition, the growing installed base of the iPad and price promotions also led to iTunes market share growth.

At the same time, Wal-Mart’s Vudu’s share of EST and iVOD movie revenue rose to 5.3% in the first half of 2011, up from 1% during the same time in 2010, rising to the third position earlier this year, up from fifth place.

The report noted that Vudu has emerged as a major market rival to established players like Apple and Sony, and gains were driven by several factors, including its shrewd device strategy, a good customer experience, a compelling user interface and its $1/$2 rental pricing system.

Microsoft’s Zune Video Marketplace, lost market share in the first half, from 18.5% to 16.2%.

Sony’s PlayStation Store accounted for 4.4% of iVOD and EST movie share in the first half, lower than 8.2% in 2010, causing the PlayStation Store to drop to the fourth position, down from third place.

Amazon’s revenue was up by 4.2% in the first half, from 4% in 2010, ranking to fifth place as the company was engaged in a shift in its business to streaming video on demand (SVOD) and Amazon Prime.

Together, the US iVOD and EST business in the first half of 2011 reached $229m, with EST accounting for $118m revenue and $111m for iVOD.

IHS predicts the market will rise to $487m in 2011, where EST revenue will reach $247m and iVOD $240m.