SANTA MONICA, Calif. – Amazon.com Inc. unveiled four new Kindle Fire models on Thursday, including ones with larger screens, as the online retailer steps up competition with Apple Inc. ahead of the holiday shopping season.

Amazon unveiled the larger Kindle Fire amid expectations of a smaller iPad from Apple.

The larger Fires will have screens that measure 8.6 inches diagonally, compared with 9.7 inches for the iPad. The original Fire had 7-inch screens. The speculation on the mini iPad is that it'll have a 7.85-inch screen. Apple isn't commenting, but it has an event scheduled next week, during which it is expected to at least announce a new iPhone.