(Adds details on results, compares with estimates, share price)
Oct 30 (Reuters) - T-Mobile US Inc beat Wall Street's quarterly estimates for net new phone subscribers who pay a monthly bill, driven by competitive wireless plans and trade-in offers for iPhones aimed at fending off its bigger rivals.
The company said it added a net 774,000 phone subscribers during the third quarter, up from 595,000 new subscribers it added last year.
Analysts on average had expected the company to add 628,000 subscribers, according to research firm FactSet.
Shares of the Bellevue, Washington-based company, rose about 4 percent to $66.5 in extended trading after its quarterly results report, which also showed revenue rising to $10.84 billion from $10.02 billion.
That was higher than analysts' estimates of $10.72 billion, according to Refinitiv data.
The third-largest U.S. wireless carrier by subscribers is awaiting approval for its deal to buy smaller rival Sprint Corp as it strives for more scale to compete with Verizon Communications and AT&T Inc.
T-Mobile's net income rose to $795 million, or 93 cents a share, in the quarter ended Sept. 30, from $550 million, or 63 cents a share, a year earlier.
Analysts were expecting the company to report a profit of 85 cents per share. (Reporting by Akanksha Rana in Bengaluru and Sheila Dang in New York; Editing by Anil D'Silva and Shounak Dasgupta)