UK's Ofcom said it was probing into the customer contract information procedure of the telecoms major following suspicion that its unit Plusnet, an internet service provider, had breached such regulatory rules.

The regulator last year October opened a probe against another BT subsidiary, mobile network operator EE, over similar non-compliance charges.

"Our investigation will now consider if BT has breached Ofcom's rules because of suspected breaches by each of these subsidiaries," the watchdog said in a statement.

(Reporting by Aby Jose Koilparambil in Bengaluru; Editing by Shinjini Ganguli)