WASHINGTON (AP) — The Interior Department is again delaying a proposed rule that would require companies drilling for oil and natural gas on federal lands to publicly disclose chemicals used in hydraulic fracturing operations.

The Obama administration first proposed a “fracking” rule last May, with a final rule expected by the end of the year. Officials later revised the timeline to early 2013. On Friday, the department pushed the deadline back again, announcing plans for a second draft version by the end of March, with publication of a final rule not expected until late 2013.