US independent Llog Exploration is reviewing development options for its Leon-Castile deep-water project in the US Gulf of Mexico as it quietly progresses towards a final investment decision.

The operator is said to be weighing up the merits of either a newbuild main production facility or an upgraded existing production unit, according to well-placed market sources.

Llog's joint venture partner, Repsol, said in its recent third-quarter report that a final investment decision for the Leon-Castile project was expected by the end of this year.