Apple's American marketshare of laptops in the second quarter of this year jumped almost two percent from the previous quarter, making it one of the Mac maker's largest laptop share increases in well over two years, Think Secret has learned.

Numbers from industry market intelligence firm IDC showed Apple's biggest marketshare increase was in U.S.-sold laptops, rising from 5.1 percent, or 146,000 units sold, in the first quarter of this year, to 7.0 percent, or 216,000 units sold.

The increase from Apple's PowerBooks and iBooks moved the company from sixth spot to fifth place among laptop makers. For comparison, IBM was in fourth place with a 9.3 percent marketshare in American laptop sales.

Among other laptop makers, the industry average increase in U.S. laptop sequential sales for the second quarter was eight percent. Apple increase was a dramatic 48 percent -- the biggest jump among all manufacturers.