Investor rumours in the US this week suggest that AT&T is mulling the acquisition of rival US operator Leap Wireless, a regional provider that specialises in low-cost mobile phone deals. The Wall Street Journal notes that speculation over a possible deal has heightened following the decision by both parties to cancel upcoming investor conferences, while shares in both operators rose in response to the speculation in trading yesterday. According to reports, Leap, which has around 4.3 million subscribers, has a market cap of around US$2.7 billion. However, one stumbling block in any deal would be the two operators’ different network platforms. AT&T uses GSM technology, while Leap is based on CDMA. Both operators declined to comment on the speculation.

If the deal were to go ahead, it would closely mirror Verizon Wireless’ acquisition of Alltel, which was completed earlier this year. AT&T is currently in the process of acquiring US$2.35 billion in Alltel assets – including some 1.5 million subscribers – that Verizon was forced to divest to meet the regulatory requirements of the deal. Like Leap, Alltel uses CDMA technology – evidence that AT&T could be willing to buy a CDMA network. Leap has made substantial gains in the US market in recent quarters as customers have flocked to its low-cost prepaid price plans. According to new Wireless Intelligence data, Leap and rival low-cost operator MetroPCS reported a record number of net additions in 1Q09, jointly capturing over 23 percent of the total US prepaid market. However, recent comments by MetroPCS CEO Roger Linquist suggest that – unlike the mooted AT&T-Leap deal – the operator is looking to buy-up smaller players rather than be acquired itself by a larger rival. Click here for Wireless Intelligence’s recent ‘Snapshot’ analysis on the latest US market share data.