No deal has been reached on the future of a lucrative shared oil deposit as a deadline expired on March 25, but Mexican state-run Pemex and Talos Energy will keep talking, three sources with direct knowledge of the matter told Reuters.

How to develop the nearly 700 million-barrel offshore Zama discovery, which was made by the Talos-led consortium in 2017, has been the subject of sensitive talks during a three-month extension provided by the energy ministry late last year.

But negotiators wrangling over operational details including who will run the project, one of the largest private oil finds in Mexico in decades, did not reach a deal as the deadline passed, the sources said.

Pemex’s media office and the energy ministry did not immediately respond to a request for comment.

A Talos representative declined to comment.

Earlier this week, Reuters reported that Pemex could consider an agreement under which Talos is the project operator if the U.S.-based company accepted certain conditions.

Two of the sources said an announcement will be made March 26, but it was unclear whether or not a formal extension to the talks would be given by the energy ministry.

The other members of the Talos-led consortium are Germany’s Wintershall Dea and Britain’s Premier Oil.

Offshore