Sydney ferries won't be free: operator

Peak-hour Sydney ferry passengers who don't buy a ticket next week will still be fined despite the maritime union saying its members will refuse to sell tickets.

The Maritime Union of Australia (MUA) has announced its members won't sell or collect tickets between 7am and 9am as well as 4pm and 6pm from June 30.

The action was declared after six months of negotiations to secure better pay conditions and investment in the fleet.

But Harbour City Ferries (HCF) says customers will have to buy a ticket from vending machines or non-union staff.

"Our customers understand we can't run free ferries, despite the best attempts of the unions to undermine our service," general manager customers and stakeholders Michelle Handforth said in a statement.

She said HCF employees were paid more than the industry standard and that the operator, which runs Sydney's ferries on behalf of the NSW government, had offered a 9.75 per cent pay increase over the next four years.

But MUA Sydney branch assistant secretary Paul Garrett says the offer they have received doesn't match inflation.

"Responsibility for this dispute's escalation lays solely at the feet of Harbour City Ferries and the state government," he said.

"The MUA has provided savings options worth millions to Harbour City Ferries and the state government, yet they still want to hold back on fair wages and hold back on proper fleet upgrades."