U.S. buyers have been snapping up the iPad so quickly that Apple Inc. is delaying the tablet computer's overseas debut a second time, the company said Wednesday.

Apple said it will now start taking orders for the iPad from international buyers on May 10.

In January, it said the iPad would be sold worldwide in late March. It started selling them in the U.S. on April 3, but delayed plans for the international launch until late in April.

Word of the second delay didn't faze Apple investors, who are eager to see signs the iPad is selling well. Apple shares rose 1.3 percent in premarket trading.

Apple said has delivered more than 500,000 iPads in the U.S. and has taken "a large number" of orders for the coming models that can go online over cellular broadband rather than solely where Wi-Fi is available. Those versions cost $629, $729 or $829, depending on the storage capacity.

The Wi-Fi-only iPads available now are $499, $599 or $699.