AT&T strenuously denied accusations by the US Securities and Exchange Commission (SEC) it disclosed non-public information to a small number of analysts in 2016.

The operator lambasted the regulator in a statement: “Tellingly, after spending four years investigating this matter, the SEC does not cite a single witness involved in any of these analyst calls who believes that material non-public information was conveyed to them.”

AT&T’s rebuttal came after the SEC filed a lawsuit against it and three of its investor relations staff with a federal district court, accusing the operator of breaking reporting rules, with the individuals in the dock for aiding and abetting.

The case surrounds comments made by AT&T executives during calls with around 20 separate analyst companies.

On the calls, the SEC claims, internal smartphone sales data illustrating a steeper than expected decline was revealed, ultimately leading the commentators to reduce revenue estimates for the operator.

This disclosure, the regulator asserts, broke rules around sharing material information.

In its response, AT&T explained the converstations took place in March and April 2016 and focused on “the widely reported, industry-wide phase-out of subsidy programmes for new smartphone purchases and the impact of this trend on smartphone upgrade rates and equipment revenue”.

“Not surprisingly, without device subsidies, customers upgraded their smartphones less frequently, leading to a reduction in equipment revenue.”

AT&T argued it publicised the trend “on multiple occasions before the analyst calls in question” and highlighted “that the declining phone sales had no material impact on its earnings”.

“The evidence could not be clearer, and the lack of any market reaction to AT&T’s first quarter 2016 results confirms, there was no disclosure of material non-public information and no violation.”