Southern Co.shares lost 0.65% to $53.79 on heavy volume to end Monday, July 11 at $53.79, aday after the company announcedplans to become an equal partner on KinderMorgan Inc.'s SouthernNatural Gas Co. LLC for $1.47 billion.

Also on Monday, Southern Co. a new corporate logo andannounced Southern Company Gasas the new name for its AGL Resources Inc. subsidiary. The merger with AGLResources created the second-largest utility company in the U.S. in terms ofcustomer base. KinderMorgan gained 3.67% to close the day at $19.22.

Shares of PatternEnergy Group Inc. advanced 1.30% on light volume to finish at$24.07. The increase in thecompany's shares came after Guggenheim Securities LLC upgraded the company'smodel and valuation based on its recent announcement to Broadview project.

"Consistent with the company's announcement, we expectthat Broadview will generate [approximately $28 million] in unlevered [cashavailable for distribution] to [Pattern Energy Group] at run-rate,"Guggenheim Securities analyst Sophie Karp said in a note to investors.The brokerage has raised the price target to $28 and reiterated the company at "buy."

Most of the merchant generators saw increases during thetrading session. Shares of MaximPower Corp. earned 3.17% to settle at C$2.93, while shares gained 2.51%to $17.55. Shares of AtlanticaYield plc were up 2.17% at $20.76.

The SNL Merchant Generator Index closed up 1.64% to 96.70.

Shares of FortisInc. rose 0.66% in weak trading to close at C$44.10, after the U.S.Committee on Foreign Investment clearedthe company's proposed $11.3 billion purchase of In its review, thecommittee concluded that the deal poses "no unresolved national securityconcerns." ITC Holdings shares earned 0.19% to $46.87 in average trading.

The SNL Energy Index went up 0.07% to 287.86, and the SNLElectric Company Index dropped 0.03% to 451.03.

Among midstream energy names, shares of saw a0.10% increase to $29.08, after it paida $1 billion final installment to acquire all the membership interests inEFS Midstream LLCfrom affiliates of PioneerNatural Resources Co. and RelianceIndustries Ltd.

AmericanMidstream Partners LP shares finished 2.27% up at $12.17 in weaktrading, after it appointedEric Kalamaras senior vice president and CFO, effective July 11. Kalamarassucceeded Dan Campbell, who was American Midstream's CFO since 2012, accordingto a news release.

The SNL Midstream Energy Index finished up 0.15% at 114.99.

In the coal space, shares of fell 50.35%to 1 cent on the over-the-counter market, after a U.S. district courtaffirmed a bankruptcycourt ruling allowing an incentive plan designed to reward the companymanagement for hitting certain targets through its reorganization.

AllianceHoldings GP LP shares shed 4.51% to $22.24 and shares of slid 2.75% to $16.99. Shares of NaturalResource Partners LP retreated 1.45% to $16.94 on thin volume.

The SNL Coal Index lost 0.92% to 56.64.

The Dow Jones Industrial Average earned 0.44% to 18,226.93,and the S&P 500 gained 0.34% to 2,137.16.

Market prices andindex values are current as of the time of publication and are subject tochange.