ETP Mariner East liquids pipe restart delayed -analysts

April 10 (Reuters) - Energy Transfer Partners LP's Sunoco Mariner East 1 natural gas liquids pipeline in Pennsylvania will likely remain out of service until late April versus a previous estimate of early April, according to analysts:

* Pennsylvania utility regulators suspended operations on the Mariner East 1 pipeline on March 7 after sinkholes were discovered near the project

* The shutdown of Mariner East 1 has forced shippers, including Range Resources Corp, to find another route for their liquids and is likely causing more ethane to be rejected into the region's natural gas pipelines, according to analysts

* In a report, analysts at Simmons & Co, energy specialists at U.S. investment bank Piper Jaffray, said Range Resources reported that Mariner East's operator said it expects the pipeline to return in late April

* Officials at Range Resources and ETP were not immediately available for comment

* Range said the outage will not cause any curtailments or shut ins of production and will minimize the effects of the outage by shifting ethane and propane volumes to other markets, according to the Simmons report

* Energy data provider DrillingInfo said in a report on Monday that the Mariner East shutdown was maxing out shipments on Enterprise Products Partners LP's ATEX pipeline, which delivers liquids from the Marcellus and Utica shale formations in Pennsylvania, West Virginia and Ohio to the Mont Belvieu storage facility in Texas

* Mariner East 1 can transport up to 70,000 barrels per day (bpd) of propane and ethane from the Marcellus and Utica shale formations in western Pennsylvania to customers in the state and elsewhere, including ETP's Marcus Hook industrial complex near Philadelphia

* Separately, ETP is building the $2.5 billion Mariner East 2 pipeline, which will boost total capacity of the Mariner East project to 345,000 bpd and open the pipe to suppliers in Ohio and West Virginia

* Since May 2017, Mariner East 2 has received 49 notices of violation from Pennsylvania regulators due in part to 110 inadvertent returns or spills, including six so far this year

* Delays related to those spills, among other things, have pushed the expected startup of Mariner East 2 from the third quarter of 2017 to the end of the second quarter of 2018 (Reporting by Scott DiSavino; editing by Jonathan Oatis)