The top aftermarket NYSE gainers Friday were: Roundy's, Rouse Properties, Genco Shipping & Trading, Delek US Holdings, USG Corp and MEMC Electronic Materials. The top aftermarket NYSE losers were: Pioneer Natural Resources, Dean Foods, ExactTarget, Drew Industries, Praxair and Drew Industries Inc.

Gainers:

Roundy's Inc. (RNDY) shares climbed 9.35 percent to $11.70 in aftermarket session.

Rouse Properties Inc. (RSE) shares surged 3.47 percent to $14.01 in post market session. The stock has a 52-week low of $10.25, a 52-week high of $15.00 and $481.30 million in market capitalization.

Genco Shipping & Trading Ltd. (GNK) shares gained 2.99 percent to $6.55 in aftermarket session.

Delek US Holdings Inc. (DK) shares rose 2.84 percent to $15.95 in aftermarket session. Delek Group, which owns approximately 68.5 percent of DK common stock, posted double digit profit and revenue growth in 2011. Its net income rose 53 percent to NIS 2.6 billion from NIS 1.7 billion last year. Operating profit increased 32 percent to NIS 1.6 billion from NIS 1.2 billion in the same period last year.

USG Corp. (USG) shares advanced 2.62 percent to $17.65 in aftermarket session. The company stock declined more than 3 percent in regular session. The company has announced the pricing of a private offering of $250 million aggregate principal amount of its 7.875 percent senior notes due 2020.

MEMC Electronic Materials Inc. (WFR) shares gained 2.22 percent to $3.69 in post market trading. The stock has a 52-week low of $3.50, a 52-week high of $13.13 and $871.02 million in market capitalization.

Losers:

Pioneer Natural Resources Co. (PXD) shares slumped 9.11 percent to $101.42 in post market trading. The company stock surged more than 6 percent in regular trading as energy stocks moved up Friday in the last session of the first quarter.

Dean Foods Co. (DF) shares plunged 3.8 percent to $11.65 in post market session. The stock has a 52-week low of $7.83, a 52-week high of $13.90 and $2.23 billion in market capitalization.

ExactTarget Inc. (ET) shares declined 3.65 percent to $25.05 in aftermarket session.

Drew Industries Inc. (DW) shares fell 2.97 percent to $26.50 in post market trading.

Praxair Inc. (PX) shares declined 2.97 percent to $111.24 in post market session. The stock has a 52-week low of $88.64, a 52-week high of $114.89 and $34.21 billion in market capitalization.

iSoftStone Holdings Ltd. (ISS) shares declined 2.69 percent to $8.59 in post market session.

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