MacBook upgrades in May proved a boost for Apple with their share of the US laptop market up nearly two points last month, according to research figures.

Stephen Baker, VP of industry analysis for NPD said: “Everybody's notebook business grew last month, but Apple's grew a little faster than the market overall. Whenever Apple gets a new product out, they get a nice bounce.”

The May boost put Apple's laptops in fourth place, behind Hewlett Packard, Toshiba, and Gateway said Baker, and moved its combined laptop-desktop sales share from 11.6% in April to 13% last month. Separately Apple notebook sales rose to 14.3% of overall purchases from 12.5%, while desktop sales increased to 10.4% from 10.2%. In retail only, sales Apple showed a slightly smaller increase, from 9.6% to 10.8%.

Apple's numbers are part of a growing trend over the past several months, according to the research company. "It's part of a pattern," Baker told InformationWeek. "Apple certainly has been gaining share over the last year to year and a half. The consumer market in general is embracing notebooks, and Apple is strong in notebooks."

Baker also claimed that desktop sales overall are declining although Apple’s sales are declining a “little less” than others. He predicted Apple would enjoy a second boost next month as back-to-school purchases begin, although this could be flatter than previous years.

Baker, like many industry observers, also anticipated a new range of iMac computers, predicting an end of July or early August launch. "I would suspect an iMac refresh would happen pretty soon. Both of the notebooks have been updated, so now it's time for Apple to look at that piece," added Baker.