DALLAS, June 12, 2012 /PRNewswire/ -- Alerian announced that following the close of business on Friday, June 15, Atlas Pipeline Partners (NYSE: APL) will be added to the Alerian MLP Index (NYSE: AMZ). Atlas owns and operates gathering and processing assets servicing natural gas producers in the Mid-Continent and Permian drilling basins of Oklahoma, southern Kansas, and western Texas. APL Shares Outstanding: 53,625,237APL Investable Weight Factor: 0.877289842883119 Alliance Holdings GP LP (NASDAQ: AHGP) will be removed from the index following the close of business on June 15. In addition, the 50 constituents of the index will be rebalanced on a float-adjusted, capitalization-weighted basis in accordance with the existing index methodology. Constituent additions to and deletions from the index do not reflect an opinion by Alerian on the investment merits of the respective securities. About the Alerian MLP Index The Alerian MLP Index is a composite of the 50 most prominent energy Master Limited Partnerships that provides investors with an unbiased, comprehensive benchmark for this emerging asset class. The index, which is calculated using a float-adjusted, capitalization-weighted methodology, is disseminated real-time on a price-return basis (NYSE: AMZ) and on a total-return basis (NYSE: AMZX). For index values, yields, constituents, and announcements regarding rebalancings, please visit www.alerian.com. About Alerian Alerian is an independent company that provides objective market information. The company is a leader in MLP-market intelligence, providing benchmarks, data sets, and analytics that are used extensively by a range of stakeholders such as investment banks, stock exchanges, investment professionals, consultants, and Master Limited Partnerships. The Alerian Index Series is used for the purposes of asset allocation, investment analysis, portfolio hedging, and the creation of index tracking funds. Over $8 billion is directly tied to Alerian's indices, including the leading benchmark of MLP equities: the Alerian MLP Index (NYSE: AMZ). For more information, please visit www.alerian.com.