Optus chairman Paul O'Sullivan has called for new laws allowing millions of internet users to quit their contracts once they are connected to the national broadband network and for Telstra to split its phone-line network from the main company.

Speaking at a Trans-Tasman Business Circle event in Sydney on Wednesday, Mr O'Sullivan said there was a lack of sufficient competition in the broadband market thanks to Telstra's success and the NBN would not fix the problem.