The top after-market NYSE gainers Thursday were Valero Energy Corp, Oasis Petroleum, Millennial Media, EXCO Resources and Hanesbrands Inc. The top after-market losers were Juniper Networks, Energy Transfer Partners, Rackspace Hosting and Salesforce.com.

Gainers

Valero Energy Corp. (NYSE:VLO) shares surged 3.72 percent to $42.98 in post-market trading. The company announced Thursday that its Board of Directors has approved the spin-off of its retail business through the distribution of 80 percent of the outstanding shares of CST Brands Inc., common stock to holders of Valero common stock.

Oasis Petroleum Inc. (NYSE:OAS) shares surged 2.65 percent to $36.04 in post-market trading. The stock has a 52-week low of $22.02, a 52-week high of $39.78 and $3.29 billion in market capitalization.

Millennial Media Inc. (NYSE:MM) shares gained 2.15 percent to $6.19 in post-market trading. The company stock plunged more than 2 percent in regular trading.

EXCO Resources Inc. (NYSE:XCO) shares advanced 2.09 percent to $6.83 in post-market trading. The stock has a 52-week low of $5.65, a 52-week high of $9.08 and $1.46 billion in market capitalization.

Hanesbrands Inc. (NYSE:HBI) shares gained 1.77 percent to $45.92 in post-market trading. The company announced that its Board of Directors has authorized the regular quarterly dividend of $0.20 per share to be paid June 3, 2013, for stockholders of record at the close of business May 20, 2013.

Losers

Juniper Networks Inc. (NYSE:JNPR) shares plunged 4.30 percent to $17.34 in post-market trading. The stock has a 52-week low of $14.01, a 52-week high of $22.98 and $9.34 billion in market capitalization.

Energy Transfer Partners L.P. (NYSE:ETP) shares plunged 4.03 percent to $48.32 in post-market trading. The company announced that it has commenced a public offering of 12,000,000 common units representing limited partner interests, with a 30-day option for the underwriter to purchase up to an additional 1,800,000 common units.

Rackspace Hosting Inc. (NYSE:RAX) shares declined 2.28 percent to $45.79 in post-market trading. The stock has a 52-week low of $40.57, a 52-week high of $81.36 and $6.42 billion in market capitalization.

Salesforce.com Inc. (NYSE:CRM) shares declined 1.93 percent to $163.19 in post-market trading. The stock has a 52-week low of $120.18, a 52-week high of $187.94 and $24.37 billion in market capitalization.

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