Energy Transfer Partners may bring on a joint venture partner for its Mariner East II NGL pipeline project, which has been delayed until the second quarter of 2018 due to construction and regulatory hurdles, according to Seeking Alpha.

Several market players consider the Mariner East II an “open secret” and have expressed disappointment with Energy Transfer for not making an official announcement months ago about the latest delay.

The project is expected to be an important conduit for the growing supply of natural gas liquids coming from the Marcellus and Utica shale plays. It will add 275,000 Bbl per day of capacity to move propane and butane. However, regulators’ have suspended the construction of a valve station on part of the line due to the release of drilling mud and sediment into streams.

Learn more: Seeking Alpha > Energy Transfer eyes JV partner for Mariner East II pipeline project