US operator AT&T today announced a new smartphone sales record, after it saw unit sales top the 10 million mark for the first time in its history during the fourth quarter of 2012, eclipsing the 9.4 million record set a full year earlier.

AT&T attributes its success to “best quarterly sales of Android and Apple smartphones,” which included the launch of Apple’s iPhone 5, which went on sale at the end of September and picked up ahead of the holiday season.

The operator announced in September that the new iPhone had overtaken the iPhone 4S as its fastest selling Apple device ever, ahead of Apple’s announcement that it had sold more than 2 million devices in 24 hours, going on to sell 5 million in its opening weekend.

As for Android, an increasing number of smartphone makers have been incorporated support for AT&T’s expanding 4G networks, which enable super-fast data speeds while on the go.

AT&T president and CEO Ralph de la Vega says that the company saw 110,000 smartphone sales a day “as customers flocked to our leading portfolio of the latest Android, Apple and Windows devices,” although he is quiet on just how well the Windows Phone operating system is performing.

In its third quarter, AT&T announced saw iPhone sales, announcing that it activated 4.7 million iPhones during the three month period – 77 percent of its 6.1 million total smartphone activations.

Today’s announcement comes before its full fourth-quarter financial report, which is due to be published on January 24.