Dubai: The head of the Abu Dhabi National Oil Company says four large tenders have been issued to develop a natural gas field in the emirate.

In comments from a speech Monday carried by state news agency WAM, Adnoc ceo Yusuf bin Omeir Bin Yusuf said the company would accept bids to develop the Shah field, but did not provide a timeframe for the project.

The field contains what is known as sour gas, which costs more to produce because it contains high levels of the toxic compound hydrogen sulfide.

Houston-based ConocoPhillips last year formed a partnership with Adnoc to produce gas from the field, but major work has yet to begin. Adnoc expects the field will eventually produce 570 million cubic feet of gas per day.