Revenue for the global notebook PC market in the first quarter of 2010 hit its highest quarterly mark since the third quarter of 2008 and in the current quarter, Apple’s iPad is taking a significant bite out of netbook market share, according to a new report from research firm DisplaySearch, a subsidiary of The NPD Group.

“The last quarter of 2007 heralded the birth of the netbook. The first quarter of 2010 signaled the birth of the slate PC, and possibly by extension, the beginning of the end of the netbook,” said John Jacobs, director of notebook market research at DisplaySearch, in a statement accompanying the report.

First-quarter sales for all notebooks grew to $31.1 billion, up 31 percent from the same period in 2009, according to DisplaySearch’s “Quarterly Advanced Notebook PC Shipment and Forecast Report” released Tuesday.

The report did note that average selling prices for notebooks in the pre-recession third quarter of 2008 were 20 percent higher than ASPs in the first quarter of 2010, a consequence of the ongoing popularity of low-priced netbooks with consumers combined with continued sluggishness in enterprise sales of more expensive mobile PCs.

The research firm further broke out the first-quarter performance of specific segments in the notebook market: revenue for netbooks and slates was $3.51 billion in the first quarter of 2010, a 56.4 percent increase year-over-year; ultraportable revenue was $1.80 billion, a 4.3 percent decrease; sales for mainstream notebooks, or portables, were $23.1 billion, a 30.7 percent hike; and desktop replacements sold to the tune of $2.93 billion, a 37.8 percent increase over the first quarter of 2009.

Apple’s iPad tablet PC, or slate, was not a factor in the netbook and slate category in terms of first-quarter revenue as it was not released to consumers until the second quarter of 2010. Still, DisplaySearch reckoned that channel shipments of the iPad by Cupertino, Calif.-based Apple accounted for 6.5 percent of the segment’s unit shipment volume in the first quarter.

Apple shipped nearly 700,000 iPads into its channel in the first quarter of 2010 and reported that it had passed the 2 million mark for unit sales in the first two months of the second quarter.

DisplaySearch projected that in the current quarter, iPad shipments will account for about 30 percent of total unit shipments in the netbook and slate segment of the overall notebook market.

That market share grab will come at the expense of netbooks, according to the research firm. Total units shipped in the netbook and slate segment peaked at 10.7 million in the fourth quarter of 2009, then dropped slightly to 10.3 million units shipped in the first quarter of 2010.

Shipment volume in the segment will further slip to 9.7 million units shipped in the current quarter, according to DisplaySearch, even as the iPad begins to approach a third of all units shipped in the netbook and slate category, and rival consumer tablet PCs based on operating systems like Google Android begin to ship as well.

“DisplaySearch expects that the iPad will continue to account for an increased share of the mini-note PC/slate segment in [the second quarter of 2010]. In the second half of the year, as additional slates are launched, the clamshell-style netbook could continue to lose share,” the research firm said in a statement.