Canada's Gabriel Resources Ltd. may lower the cyanide levels at a long-delayed Romanian gold mine project as it seeks to secure a key environmental permit, a company official said on Thursday.

Gabriel owns roughly 80 percent of Rosia Montana Gold Corporation, the company that plans to build Europe's biggest open cast gold mine in the Carpathian town of Rosia Montana, with the Romanian government holding a 19 percent stake.

The 14-year old project, which plans to use cyanide to mine 314 tonnes of gold and 1,500 tonnes of silver, faces strong opposition from rights groups, ecologists and neighbouring Hungary, which argue the mine would destroy ancient Roman gold mines in the area, the environment and nearby villages.

Romanian Environment Minister Laszlo Borbely said last month he had asked Gabriel to lower the amount of cyanide it would use in a tailing pond near the open cast mine.

The project currently envisions using a cyanide level of five parts-per-million, half the European Union's allowed ceiling and Cecilia Szentesy, a director of Rosia Montana Gold Corporation said the level could be lowered to three parts-per-million.

It can be done for 80-85 percent of total output, Szentesy told an energy seminar. There are several solutions.

Romanian officials, including Prime Minister Emil Boc have recently said the contract with Gabriel may need renegotiation to ensure the country gets the most out of the project.

Rosia Montana Gold Corporation has estimated the 10-ounce gold mine is worth $7.5 billion and said Romania would get a little over $4 billion of that in direct taxes, dividends, service providers and jobs.

The economy ministry said on Thursday it agreed with the assessment, based on a 2007 study that used an average price of $900 per gold ounce.

We think the state's share is already fairly competitive, but we are willing to have any type of talks with the state, Szentesy said.