When AT&T announces its first-quarter results next Tuesday, investors will be looking for evidence that the recent surge in wireless data revenues at US telecoms companies is continuing.

Revenues from wireless data services in the US rose 53 per cent to $23bn last year according to figures prepared for CTIA Wireless, a Washington-based industry trade group. Overall, revenue from e-mail, text and picture messaging, and other non-voice services accounts for about 17 per cent of total wireless revenues.