The NSW compulsory third-party (CTP) scheme is on an unsustainable path, according to Suncorp Commercial Insurance EGM Chris McHugh.

Suncorp, which holds 20% of the market through GIO and AAMI, will take part in a government roundtable on the scheme on Wednesday.

The insurer has restated its position that proposed reforms to the greenslip system will create a clear and consistent claims process that is faster and more efficient, therefore reducing costs.

While premiums have risen about 50% in recent years, less than 50 cents in every dollar goes to injured people, Mr McHugh says in a letter published by the Sydney Morning Herald.

The NSW Government wants to create a no-fault scheme that it says could reduce average premiums by 15% and ensure benefits are paid sooner.

But CTP has become dogged by controversy surrounding Finance Minister Greg Pearce and links to insurance lobbyists.

Insurers are divided on how soon the reforms should be introduced, according to reports.

Last month the Government said it would delay the reforms because it could not get them through the Legislative Assembly. It then announced the roundtable to hear stakeholder views.

The average CTP premium has risen 9% annually since 2007, about three times the rate of inflation. In February it was increased to more than $500 from less than $450 for passenger vehicles.