BT Group PLC (LON:BT.A) has been fined £6.3mln by Ofcom for breaking the regulator’s rules during the tender process for a public sector telecoms contract in Northern Ireland over 2017 and 2018.

On Friday, Ofcom said the telecoms firm’s network division had failed to give rival company Eir the same information as its own bid team about one of its wholesale products during the tender process.

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Under the rules, BT must treat all its wholesale customers equally, as most firms rely on the company’s network to provide their services.

These are designed to help alleviate competition concerns arising from what Ofcom said was BT’s “significant market power” and ensure a level playing field upon which other providers can compete.

“BT’s network arm broke our rules by failing to treat a rival company and BT’s own bid team equally during the tender for a major public sector contract in Northern Ireland. Our fine reflects how important these rules are, and how seriously we take compliance”, Ofcom’s director of enforcement Gaucho Rasmussen said in a statement.

BT shares were down 2.6% at 132.2p in mid-afternoon trading.