AT&T Inc. added more mobile phone and home internet subscribers this summer than analysts expected, amid a heavy promotional push to keep competitive pressure on its two main rivals.

The smallest of the Big Three US wireless providers, AT&T won 405,000 new mobile phone customers in the third quarter, according to a statement Wednesday, up slightly from a year earlier and topping analysts’ average projection for 338,500. The company also added 288,000 fiber internet customers, exceeding expectations of 273,747.