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.

Interior Department spokesman Blake Androff said the administration is committed to responsible expansion of domestic oil and gas production, but said it is important that the public have confidence that proper environmental protections are in place.