U.S. buyers have been snapping up iPads so quickly that Apple is delaying the tablet computer’s overseas debut a second time, the company said on 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. After analysts reported production delays would limit the number of units available, Apple postponed the U.S. launch to April 3 and 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. “We know that many international customers waiting to buy an iPad will be disappointed by this news, but we hope they will be pleased to learn the reason — the iPad is a runaway success in the U.S. thus far,” Apple said in a statement.

Apple said has delivered more than 5,00,000 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.