AT&T experienced heightened profit and revenue in Q3 thanks in part to a surge in valuable postpaid mobile subscribers.

The second largest US operator reported net earnings of $3.8 billion in the quarter compared to $3.6 billion in the same period last year. Revenue rose 2.2 per cent to $32.2 billion.

It added 363,000 net new mobile subscribers on postpaid contracts during the third quarter, a figure which was well ahead of last year’s 151,000.

Of AT&T’s postpaid base, 75 per cent now have smartphones, an increase from 66 per cent a year ago.

The company’s overall results were also aided by a strong performance from the operator’s U-verse fibre service.

Wireless operating revenue grew by 5.1 per cent to $17.5 billion while fixed revenue fell by 1 per cent to $14.7 billion, despite the contribution of U-verse.

However, despite its improved performance AT&T still lags larger rival Verizon Wireless, which last week also reported a strong quarter. It also faces competition from a rejuvenated T-Mobile US.

Earlier this week, AT&T unveiled a $4.85 billion cash deal to sell or lease nearly 10,000 cell towers to Crown Castle. The sum approximately doubles its cash reserves, giving it additional firepower for its ongoing network upgrade, as well as chasing further spectrum buys and a much mooted international acquisition.