NTT DoCoMo Inc., the nation's biggest mobile-phone operator, posted the first monthly decline in subscriptions in more than five years as Softbank Corp. and KDDI Corp. lured customers with Apple Inc.'s iPhone 5.

DoCoMo, the only one of the three top wireless operators that doesn't offer the iPhone, lost 40,800 net subscribers in November, it said in a statement Friday.

That's the first monthly drop since August 2007, according to data from the Telecommunications Carriers Association, an industry group. KDDI and Softbank both posted increases in subscriptions last month, they said in separate statements.