May 6 (Reuters) - Atlas Energy Operating Co LLC, a
subsidiary of Atlas Energy (ATN.N: Quote, Profile, Research), the natural gas producer,
on Tuesday added $150 million to its existing 10.75 percent
senior notes due February 2018 in the 144a private placement
market, said market sources.

The total amount of notes now outstanding is $400
million.

The size of the deal was increased from the originally
planned $100 million.

JP Morgan and Wachovia Securities were the joint
bookrunning managers for the sale.
BORROWER: ATLAS ENERGY OPERATING CO LLC/

FINANCE CORP
AMT $150 MLN COUPON 10.75 PCT MATURITY 2/1/2018
TYPE ADD-ON NTS ISS PRICE 104.750 * FIRST PAY 8/1/2008
MOODY'S B3 YIELD 9.970 PCT SETTLEMENT 5/9/2008
S&P SINGLE-B SPREAD 607 BPS PAY FREQ SEMI-ANNUAL
FITCH N/A MORE THAN TREASURY NON-CALLABLE 5-YEARS**
* PLUS ACCRUED INTEREST FROM 1/23/2008
** NON CALLABLE 5-YEAR(2/1/2013).THEN AT 105.375, 103.583,

101.792, 100.
*** EQUITY CLAWBACK 35% AT 110.75 UNTIL 2/1/2011.