UPDATE 2-Apple says iPad 3G available on April 30

* iPad sales strong in early going

* International roll-out in May

(updates with background, share price)

NEW YORK, April 20 (Reuters) - The high-speed mobile version of Apple Inc's (AAPL.O) iPad will hit store shelves on April 30, and international pricing for the tablet computer will be spelled out on May 10, the company said on Tuesday.

The company sold more than 500,000 units of its Wi-Fi-only iPad in the U.S. in the week after its April 3 launch.

Many analysts expect Apple to sell roughly 5 million iPads this year, although estimates vary widely. The device starts at $499.

Demand is expected to remain high with the launch of the version that connects to AT&T's third generation -- or 3G -- wireless network.

The 3G device will go on sale at April 30 in Apple retail stores, and will also be delivered to U.S. customers who preordered the unit.

The 3G model has been available for preorder since mid-March. However, customers currently ordering the device through Apple's online store are told that their 3G-enabled iPad will ship by May 7.

Apple is set to report quarterly results after market close on Tuesday, with Wall Street eager for an update on iPad sales. Apple shares slipped less than 1 percent to $245.08 in midday trading on the Nasdaq.[ID:nN16129038]

The 3G model, which also operates via Wi-Fi, will cost an additional $130, meaning that the 16GB, 32GB and 64GB models will cost $629, $729 and $829, respectively.

Last week Apple said it would delay the international introduction of the iPad for one month, due to heavy demand in the United States.

Analysts say the company has faced some hurdles in its supply chain as it ramps production of a new class of device, one that fuses the functionality of a laptop with the portability of a smartphone. [ID:nN14141613]

The iPad -- which has a 9.7-inch color touchscreen for surfing the Web, watching movies, playing games and sending email -- will be available at the end of May in Australia, Canada, France, Germany, Italy, Japan, Spain, Switzerland and the UK.

The company will announce international pricing and begin taking online preorders on May 10.

International carriers include Vodafone Group (VOD.L) and Orange (FTE.PA). (Reporting by Franklin Paul and Gabriel Madway; Editing by Derek Caney)