NEW YORK ( TheStreet) -- GT Solar (SOLR), JA Solar Holdings (JASO - Get Report), Helix Energy Solutions (HLX - Get Report) and Energy XXI (Bermuda) (EXXI - Get Report) were top performers this week, while Vestas (VWRDY), Aventine Renewable Energy Holdings (AVRW) and LDK Solar (LDK) eroded substantial ground.
Among the advancers, GT Solar topped the charts, jumping 18.2%. Ardour Capital reiterated a buy on the stock on improved prospects from the company's Sapphire business.
JA Solar rose 10.5% and Helix Energy Solutions gained 8.3% the week of June 20.
Energy XXI (Bermuda) advanced 8.3%. Analysts at Rodman & Renshaw maintained market perform on the stock and observed higher-than-expected production.
Other winners were
Holly Energy Partners
Cheniere Energy Partners
piled 6.3% each.
Bill Barrett Corporation
moved up 6.2%. Global Hunter Securities equity analyst Michael Bodino rated a new accumulate on the stock with a 12-month target price of $59 per share.
gained 6% during the week.
Oil States International
rose 5.5% after its subsidiary secured a contract from Subsea 7 to supply 27 FlexJoint Steel Catenary Riser terminations and 40 receptacle assemblies for the Guara and Lula NE oilfields in Brazil.
Other movers were
Teekay LNG Partners
rose 5%, and
added 4.7% during the week.
advanced 5%. Analysts at Maxim Group rated a new buy on the stock with a price target of $22 per share.
PAA Natural Gas Storage
closed the week with gains of more than 4%.
Vestas was the top lagger, shedding 13.3%. Citi rated a sell on the stock on stretched valuations. The brokerage says the company could miss its year-over-year order intake growth for 2011 of 7 to 8 GW.
Aventine Renewable Energy Holdings declined 5.9% and LDK Solar lost 5.3% during the week.
erased 4.6%. S&P revised Encana's outlook to negative on closure of PetroChina joint venture.
Niska Gas Storage Partners
pared 4.2%. UBS lowered its price target on the stock to $19 per share from $20 and maintained a neutral rating on it.
fell 4.2%. Analysts at Raymond James downgraded the stock to market perform from strong buy.
Others on the downside were
losing 2.5% and