BT has criticised Sky after it renewed its calls for a full separation of its infrastructure division Openreach.
Earlier this week, Sky's Chief Operating Officer Andrew Griffith argued that a fully independent Openreach would offer a higher quality service, treat all its customers equally and be able to reinvest its profits in network improvement.
However, BT Chief Executive Gavin Patterson has disputed this view, insisting that breaking up BT would undermine network investment, ISPreview.co.uk reports.
"It takes the whole of BT Group to make the case for massive network investments," he said.
"Openreach cannot do it on its own. Those arguing that splitting BT will boost investment fail to appreciate the huge risks."
Mr Patterson warned that separating BT and Openreach would "cost billions" and said this money would be better spent on investment in networks.
Furthermore, he stressed that Openreach's status as part of the BT Group enables it to benefit from lower funding costs, access to "massive" R&D facilities and the ability to spread risk across a bigger business.
"And because it serves more than 500 communications providers on equal terms, these benefits flow to the whole industry," Mr Patterson said.
Ofcom has ordered BT to give more independence and investment powers to Openreach, with the broadband subsidiary being run as a distinct and legally separate company with its own board.
The watchdog believes its proposals will provide Openreach with the greatest possible degree of independence without separating the companies entirely, and lead to decisions being taken for the good of its customers and the wider telecoms industry.
"In July, we made a proposal to Ofcom for reforms of Openreach to further strengthen its independence, which would preserve these benefits while minimising disruption and cost," Mr Patterson stated.
"We believe this is the best way to deliver the UK’s digital future.”