Optus has threatened to pull out of the bidding to build the $9 billion national broadband network unless the Federal Government extends the deadline.

In addition, Optus CEO Paul O'Sullivan said he wants an assurance from the government there will be "structural separation" between ownership and service provision on the new network

O'Sullivan was talking on ABC-TV's Sunday business program Insiders. Optus is a major player in the so-called G9 consortium which is now working on a bid.

He said Optus wants a five-month extension to the July 25 deadline from the moment when crucial information about existing infrastructure is released to the bidders.

On structural separation, O'Sullivan said "what we're looking for is a confirmation that, in common with other markets in the OECD (Organisation for Economic Cooperation and Development), government will make sure that this bottleneck infrastructure is run in a way that is structurally separated and provides competition."

Without structural separation, he said Telstra could end up with a monopoly control over the infrastructure while also setting prices and access terms to the network. "Their track record on that is disgraceful," O'Sullivan said.

 Communications Minister Stephen Conroy said late last week he would stick to the July 25 deadline despite strong protests from bidders, including Optus.