Enterprise Products and Duncan Energy Increase Capacity of Haynesville Extension Project

Enterprise Products Partners L.P. (NYSE:EPD) and Duncan Energy Partners L.P. (NYSE:DEP) today announced they have received additional firm transportation commitments from shippers sufficient to support an increase in the capacity of its recently announced Haynesville Extension project from 1.4 billion cubic feet per day (Bcf/d) to 2.1 Bcf/d. As a result, Enterprise and Duncan Energy placed an order today increasing the size of the 249-mile pipeline extension of their jointly-owned Acadian Gas LLC intrastate pipeline into Northwest Louisiana to 42 inches in diameter.

Following its completion, which is expected in September of 2011, the project will provide producers in the rapidly growing Haynesville Shale play with much needed takeaway capacity, including access to more than 150 end-use markets along the Mississippi River corridor between Baton Rouge and New Orleans. In addition, shippers will be able to access a rapid-cycle salt dome storage cavern and have the ability to make physical deliveries into the Henry Hub and benefit from more favorable pricing points. The Haynesville Extension will also allow shippers to reach nine interstate pipeline systems.

Acadian Gas, LLC is 66 percent owned by Duncan Energy Partners and 34 percent owned by Enterprise Products Partners. Enterprise Products Partners is the parent of Duncan Energy Partners and currently owns approximately 52 percent of the outstanding common units of DEP, in addition to significant direct equity interests in each of Duncan Energy’s subsidiaries.

Enterprise Products Partners L.P. is the largest publicly traded partnership and a leading North American provider of midstream energy services to producers and consumers of natural gas, NGLs, crude oil, refined products and petrochemicals. The partnership’s assets include: more than 48,000 miles of onshore and offshore pipelines; approximately 200 million barrels of storage capacity for NGLs, refined products and crude oil; and 27 billion cubic feet of natural gas storage capacity. Services include: natural gas transportation, gathering, processing and storage; NGL fractionation (or separation), transportation, storage, and import and export terminaling; crude oil and refined products storage, transportation and terminaling; offshore production platform; petrochemical transportation and storage; and a marine transportation business that operates primarily on the United States inland and Intracoastal Waterway systems and in the Gulf of Mexico. For additional information visit www.epplp.com. Enterprise Products Partners L.P. is managed by its general partner, Enterprise Products GP LLC, which is wholly owned by Enterprise GP Holdings L.P. (NYSE:EPE). For more information on Enterprise GP Holdings L.P., visit www.enterprisegp.com.

Duncan Energy Partners is a publicly traded partnership that provides midstream energy services, including gathering, transportation, marketing and storage of natural gas, in addition to NGL fractionation (or separation), transportation and storage and petrochemical transportation and storage. Duncan Energy Partners owns interests in assets located primarily in Texas and Louisiana, including interests in approximately 9,200 miles of natural gas pipelines with a transportation capacity aggregating approximately 6.8 billion cubic feet ("Bcf”) per day; more than 1,600 miles of NGL and petrochemical pipelines featuring access to the world’s largest fractionation complex at Mont Belvieu, Texas; two NGL fractionation facilities located in south Texas; approximately 18 million barrels ("MMBbls”) of leased NGL storage capacity; 8.5 Bcf of leased natural gas storage capacity; and 34 underground salt dome caverns with more than 100 MMBbls of NGL storage capacity at Mont Belvieu. Duncan Energy Partners is managed by its general partner, DEP Holdings, LLC, which is a wholly-owned subsidiary of Enterprise. Additional information about Duncan Energy Partners is available online at www.deplp.com.

This press release includes forward-looking statements. Except for the historical information contained herein, the matters discussed in this press release are forward-looking statements that involve certain risks and uncertainties, such as the partnership’s expectations regarding future results, capital expenditures, project completions, liquidity and financial market conditions. These risks and uncertainties include, among other things, insufficient cash from operations, adverse market conditions, governmental regulations and other factors discussed in Enterprise’s filings with the U.S. Securities and Exchange Commission. If any of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results or outcomes may vary materially from those expected. The partnership disclaims any intention or obligation to update publicly or reverse such statements, whether as a result of new information, future events or otherwise.