The deal reportedly extends to the first 500,000 of the new iBooks that will be manufactured and debunks an earlier DigiTimes report that said Quanta secured the same order back in April.
Apple's current offerings include both a 12.1- and 14.1-inch iBook G4 laptop, but neither features a widescreen display. The smallest profile Apple laptop to sport a widescreen is its 15.2-inch PowerBook G4.
The overseas report also cites unnamed sources in saying Asustek also recently secured orders for the 15.4-inch iBook, which will be launched in 2006.
The reliability of the report is unknown and Asustek declined to comment, stating it has non-disclosure agreements with all of its OEM customers.
According to the report, last year Asustek shipped more than one million notebooks to Apple, including 12.1-inch iBooks and 12.1-inch PowerBooks.
Asustek is also believed to be one of two Taiwanese manufacturers contracted by Apple to produce its iPod shuffle digital music player.
Meanwhile, Quanta retains contracts to produce Apple's iMac G5, Xserve G5, and certain PowerBook G4 models.