Sunoco Logistics Partners L.P. (NYSE: SXL) today announced that it will commence a binding Open Season for Project Mariner West. Mariner West is a pipeline project developed jointly by Sunoco Logistics and MarkWest Liberty Midstream & Resources, LLC, a partnership between MarkWest Energy Partners, L.P. (NYSE: MWE) and The Energy & Minerals Group to deliver ethane from the liquid-rich Marcellus Shale processing and fractionation areas in Western Pennsylvania to Marysville, Michigan and the international border near Marysville, Michigan. The project is anticipated to have an initial capacity to transport up to 50,000 barrels per day of ethane and can be scaled to support higher volumes as needed. Mariner West is scheduled to be operational by July 2013 to meet the expectations of the ethane producers and consumers.

Together with Mariner East, a previously announced Sunoco Logistics/MarkWest Liberty pipeline and marine project developed to transport ethane produced in the Marcellus to the US Gulf Coast, these projects provide Marcellus producers with a comprehensive ethane takeaway solution for the Marcellus Shale basin.

The Open Season will commence on July 21, 2011 and will end August 22, 2011. Priority service will be available to shippers making long-term volume commitments during the Open Season. The Notice of Open Season will be available on the Sunoco Logistics website at www.sunocologistics.com/marinerwest.

More information about this Open Season is available by contacting:

Hank Alexander
215-246-8568
hjalexander@sunocologistics.com

ABOUT SUNOCO LOGISTICS

Sunoco Logistics Partners L.P. (NYSE: SXL), headquartered in Philadelphia, is a master limited partnership that owns and operates a logistics business consisting of a geographically diverse portfolio of complementary pipeline, terminalling and crude oil acquisition and marketing assets. The Refined Products Pipeline System consists of approximately 2,500 miles of refined products pipelines located in the northeast, midwest and southwest United States and equity interests in four refined products pipelines. The Terminal Facilities consist of approximately 39 million shell barrels of refined products and crude oil terminal capacity (including approximately 21 million shell barrels of capacity at the Nederland Terminal on the Gulf Coast of Texas and approximately 5 million shell barrels of capacity at the Eagle Point Terminal on the banks of the Delaware River in New Jersey). The Crude Oil Pipeline System consists of approximately 5,400 miles of crude oil pipelines, located principally in Oklahoma and Texas.

Statements in the foregoing announcement that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act. These forward-looking statements are based upon assumptions by Sunoco Logistics Partners L.P. (the "Partnership") concerning future conditions, any or all of which ultimately may prove to be inaccurate, and upon the current knowledge, beliefs and expectations of Partnership management. These forward-looking statements are not guarantees of future performance. Although we believe such assumptions are reasonable, investors are strongly cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this announcement, and which involve risks and uncertainties that may affect our business and cause actual results to differ materially from expectations. Such risks and uncertainties include, by way of example and not of limitation: our ability to consummate the announced acquisition and successfully integrate it into our existing operations, at the price and within the timeframe announced; potential changes in market factors (competition; supply, or demand) affecting the assets to be acquired; and possible changes in operating conditions and costs. Additional risks and uncertainties include economic, business, competitive and/or regulatory factors affecting our business, as well as uncertainties related to the outcomes of pending or future litigation, legislation, or regulatory actions. Unpredictable or unknown factors not discussed in this release also could have a material adverse effect on forward-looking statements. The Partnership has included in its Annual Report on Form 10-K for the year ended December 31, 2010, and in its subsequent Form 10-Q and Form 8-K filings, cautionary language identifying other important factors (though not necessarily all such factors) that could cause future outcomes to differ materially from those set forth in the forward-looking statements. For more information concerning these factors, see the Partnership's Securities and Exchange Commission filings, available on the Partnership's website at www.SunocoLogistics.com. The Partnership expressly disclaims any obligation to update or alter its forward-looking statements, whether as a result of new information, future events or otherwise.

Sunoco Logistics Partners L.P.
Thomas Golembeski (media) 215-977-6298
or
Peter Gvazdauskas (investors) 215-977-6322