The premiers of Nova Scotia and Newfoundland and Labrador left empty-handed following Tuesday's marathon talks with Ottawa on an offshore gas revenue deal.

Newfoundland and Labrador Premier Danny Williams and Nova Scotia Premier John Hamm met with federal officials, including Finance Minister Ralph Goodale, for about 10 hours Tuesday in St. John's.

The two provinces want to keep 100 per cent of their offshore revenues, without it being clawed back from equalization payments.

Williams said late Tuesday he is optimistic following the meeting, which saw the federal government change its position on two other key issues.

A sunset clause, which could run the clock out on a new offshore revenue deal, appears to be the main issue keeping the Ottawa and the governments apart, he said.

The Nova Scotia premier calls that condition a deal breaker, because a sunset clause closes the door on benefits from future offshore oil and gas benefits.

"Those projects would be beyond an eight-year time frame, so that's why in Nova Scotia everyone is focusing very, very acutely on the sunset clause," said John Hamm.

Goodale said he is willing to keep talking.

"We are not done yet," he said.

"There are some serious issues remaining. But I want to assure you that Canada will stick with it. We will continue to be constructive, we will continue to be creative."

Loyola Sullivan, the finance minister of Newfoundland and Labrador, is scheduled to meet with Nova Scotia Energy Minister Cecil Clarke Wednesday.

No timetable has been set for the premiers to meet again with Goodale.

Williams walked out of the first ministers meeting on equalization in October, after finally receiving a written response from the federal government.

Williams wants the federal government to commit to a verbal promise made by Prime Minister Paul Martin during June's election campaign.