Apple announced expanded LTE coverage in its new iPad mini and fourth generation iPad with Retina display. Several LTE radio options are supported.
In the U.S. market, iPad LTE service will now be available from AT&T, Sprint and Verizon.
International LTE Coverage
Canada -- Bell, Rogers, Telus
Germany -- Deutsche Telekom
UK -- EE
Australia -- Optus
Japan -- KDDI, Softbank
Korea -- SK Telecom, KT
Hong Kong -- Hurchison, SmarTone
Singapore -- M1, SingTel, StarHub
http://www.apple.com/ipad/LTE/