Apple gained market share with its Macintosh line of computers in the U.S. during the March quarter, even though sales were off year-over-year, according to research firm IDC. For the quarter, Apple sold some 1.13 million Macs in the U.S. While down from the 1.44 million units IDC reported for Q1 2008, the market as a whole dipped far more than Apple's sales, representing a market share gain for the company, up from 7.4% in 2008 to 7.6% in 2009.

Apple was the #4 computer vendor in the U.S., behind Acer (#3), Dell (#2), and HP (#1), and ahead of Toshiba (#5). Apple, Acer, Toshiba, and HP all gained market share during the quarter, while Dell, alone of the top five, posted a drop in market share of 1.6 percentage points (from 15.2% to 13.6%).

"Dell had a tough quarter across the board," IDC said in a statement. "though it fared better in some emerging regions. A weak Commercial market resulted in faster declines in Desktops while its Portable sales struggled to address competition and the shift to low priced consumer systems."

(There's no word yet if Dell's leadership is planning on selling off the company's assets and return the money to the shareholders.)

Overall, IDC said that the U.S. computer market turned out to be "surprisingly resilient" in the face of tough economic times. According to the company, notebook purchases were still seen as "important" by many consumers, and it was the portable end of the market that drove sales.

Sales in the U.S. dipped 3%, a much better performance than IDC had been expecting, and better than the global market, where sales dipped some 7.1%. Even that number was better than expected, however, as IDC had projected an 8.2% decline.

Apple's unit expected unit sales in the 2-2.6 million unit range are not enough to give the company a spot in the top five global vendors. Toshiba's position as #5 with some 3.44 million units is far ahead of Apple. Lenovo (#4), Acer (#3), Dell (#2), and HP (#1) rounded out the top five.