Sunoco Logistics Partners L.P. is withdrawing requests to override local zoning ordinances for its Mariner East pipeline project, tidying up a legal mess it created over the controversial Pennsylvania pipeline.

The Philadelphia pipeline company on Thursday asked the Pennsylvania Public Utility Commission to withdraw the last nine of 31 requests for exemptions to local zoning rules.

Sunoco said it has secured the local zoning approvals it needed for pump stations and valve stations along the 299-mile route, or has modified its project so that a zoning exemption is no longer required. Last month it withdrew applications for exemptions in 22 other towns.

Since its requests are now moot, "no case or controversy is presented any longer within the jurisdiction of the PUC," Sunoco told the commission.

The filing appears to allow the company to extricate itself from a legal thicket over Mariner East, which calls for repurposing an 84-year-old pipeline to transport Marcellus Shale natural gas liquids such as ethane and propane to Sunoco's terminal in Marcus Hook, whence the fuel would be exported or distributed locally.

Pipeline opponents vowed to continue to fight. "No one should think this is over and done with," said Tom Casey, a spokesman for the Chester County Community Coalition.

Sunoco applied for the exemptions a year ago, and then refiled its application, arguing that as a public utility corporation, the structures on its pipeline are necessary for the convenience or welfare of the public and therefore exempt from local regulation.

Two administrative law judges sided with opponents who argued that the pipeline was not a public utility. The PUC overruled them in October, directing the judges to confine their examination to the narrow issue of whether the structures surrounding Sunoco's pump stations should be exempt from zoning.

Sunoco began sending propane into the pipeline in December. The additional pumping capacity would allow the pipeline to carry up to 70,000 barrels of ethane a day.

Sunoco is planning a second Mariner East pipeline adjacent to the first, inciting more opposition because it will involve entirely new construction.