Apple extended its dominance in tablet computers, shipping nearly seven out of every 10 tablets in the second quarter, according to research firm IHS iSuppli.

A new model came out a few weeks before the April-June quarter began. Google's challenger, the Nexus 7, didn't start shipping until the third quarter.

Apple's 69.6 percent share in the April-June quarter is up from about 58 percent in the first quarter. It's the highest since the first quarter of last year, when Apple had 70 percent in a market with fewer competitors then.

Here are the top five manufacturers of tablets in the second quarter, as released by HIS iSuppli on Tuesday:

Apple Inc., maker of the iPad, 17 million shipped worldwide, 69.6 percent share

Samsung Electronics Co., maker of Galaxy line, 2.3 million, 9.2 percent.

Amazon.com Inc., maker of Kindle Fire, 1 million, 4.2 percent

AsusTek Computer Inc., maker of Transformer line, 688,000, 2.8 percent

Barnes & Noble Inc., maker of Nook Tablet, 459,000, 1.9 percent

Other, 3 million, 12.3 percent

Source: IHS iSuppli