NEW YORK (Karvy) -- GT Solar (SOLR), LDK Solar (LDK) and Yingli Green Energy (YGE) emerged as top gainers last week, while InterOil (IOC), McMoRan Exploration (MMR) and TransAtlantic Petroleum (TAT - Get Report) led the losers' list.

GT Solar gained 9.8%, topping the list of energy gainers. During the week, the company announced a new DSS650 Multicrystalline Ingot Growth System. Tom Gutierrez, GT Solar's president and CEO, said in a press release, "GT Solar continues to actively invest in advanced technologies that deliver value to our customers. Our field-tested DSS650 sets a new standard for cost-effective, high volume, multicrystalline silicon ingot growth systems greater than 600 kilograms, which help PV manufacturers lower their production costs and improve their competitive position." Meanwhile, the company has received a $33.3 million order for sapphire crystallization from South Korea-based OCI.

Other solar stocks LDK Solar, Yingli, Trina Solar ( TSL) and First Solar ( FSLR - Get Report) advanced around 6.8%, 6.7%, 4.3% and 4.1%, respectively.

EnCana ( ECA - Get Report) rose 5%. During the week, Western Gas Partners ( WES - Get Report), a subsidiary of Anadarko Petroleum ( APC), agreed to purchase Encana's Ft. Lupton processing plant in the DJ Basin of northeastern Colorado for $303.3 million.

Nexen ( NXY) advanced around 3.8%, after FirstEnergy Capital raised the stock to market perform. Analysts at Haywood Securities, however, downgraded the stock to sector perform. Meanwhile, Nexen announced it will sell its 65% stake in chemical company Canexus for C$477.1 million ($481 million) to a syndicate of underwriters.

French oil giant Total ( NXY) rose around 3.6% last week. Total Capital Canada and Total Capital, units of Total, sold around $2 billion of notes in a three-part offering. In the penultimate week, Total acquired interests in four exploration licenses in Argentina, in partnership with YPF ( YPF), to appraise the shale gas potential of these assets.

Cabot Oil & Gas ( COG) gained 3% after Morgan Stanley upgraded the stock to overweight with a $45 price target, implying a 15.1% upside from the current level.

Energy giants Exxon Mobil ( COG), Royal Dutch Shell ( RDS.A - Get Report), Sunoco ( SUN) and Chevron ( CVX - Get Report) posted gains of 3%, 2%, 1.9% and 1.7% last week, respectively.

Eni ( E) and El Paso ( EP) were up 2.9% and 2.8% during the week, respectively. RBS upgraded Eni to buy from hold, while Citi raised El Paso to buy from hold.

Occidental Petroleum ( OXY - Get Report) surged around 1.6% after signing an agreement with the Abu Dhabi government to develop the Shah natural gas field.

Other winners include Precision Drilling ( PDS), Noble Energy ( NBL), EOG Resources ( EOG) and Penn West Energy Trust ( PWE), up 4.7%, 4%, 3.9% and 3.5%, respectively.

InterOil was the top loser, down 10.4%, falling below its 50-day moving average on concerns of potential project delays. McMoRan Exploration lost 10.1% after fourth-quarter losses widened due to charges and write-downs.

Teekay LNG Partners ( TGP) and Petrohawk Energy ( HK) shed 6.8% and 6.7% last week, respectively. Citi cut Teekay to hold from buy. Tudor Pickering downgraded Petrohawk to hold from buy.

Rosetta Resources ( ROSE) declined 5.8% after Howard Weil cut the stock to market perform while cutting the rating to trim from hold.

DCP Midstream Partners ( DPM) dipped 5.3%, despite receiving an upgrade to buy at Citi. During the week, DCP signed a long-term gas gathering, processing agreement with Pioneer Natural Resources ( PXD), Reliance Eagleford Upstream and Newpek.

Among other losers were Petrobras Energia Participaciones ( PZE), SandRidge Energy ( SD), Swift Energy ( SFY), Cheniere Energy Partners ( CQP) and Cobalt International Energy ( CIE) dropping around 7.4%, 7%, 6.2%, 6.1% and 6.1%, respectively.

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