The top after-market NYSE gainers Thursday were SuperValu Inc, Tahoe Resources, Black Hills Corp, Yingli Green Energy Holding and McEwen Mining Inc. The top after-market NYSE losers were Salesforce.com, Solera Holdings, Hormel Foods, General Growth Properties and Sprint Nextel Corp.

Gainers

SuperValu Inc. (SVU) shares climbed 10.38 percent to $2.34 in post-market trading on news that the company advisers are asking potential buyers to bid for the entire business even as several suitors have inquired about individual parts of the grocery company, Bloomberg reported citing people with knowledge of the matter.

Tahoe Resources, Inc. (TAHO) shares surged 4.27 percent to $19.55 in post-market trading. The stock has a 52-week low of $8.55, a 52-week high of $24.01 and $2.66 billion in market capitalization.

Black Hills Corp. (BKH) shares surged 2.93 percent to $31.92 in post-market trading. The company announced Thursday that its oil and gas subsidiary, Black Hills Exploration & Production, Inc., signed a definitive agreement to sell approximately 85 percent of its Bakken and Three Forks shale assets in the Williston Basin for approximately $243 million.

Yingli Green Energy Holding Co, Ltd. (YGE) shares gained 2.31 percent to $2.10 in post-market trading. The company stock plunged nearly 2.4 percent in regular trading.

McEwen Mining Inc. (MUX) shares rose 2.28 percent to $4.03 in post-market trading. The stock has a 52-week low of $1.96, a 52-week high of $6.49 and $1.06 billion in market capitalization.

Losers

Salesforce.com Inc. (CRM) shares slumped 5.09 percent to $139.30 in post-market trading. Its second quarter net loss widened to $9.8 million or $0.07 per share from $4.3 million or $0.03 per share in the same period last year. The company expects that the third quarter adjusted earnings will be in a range of $0.31 to $0.32 per share compared to analysts' estimate of $0.34 per share.

Solera Holdings, Inc. (SLH) shares plunged 3.96 percent to $41.00 in post-market trading. The company expects that fiscal 2013 adjusted earnings will be in a range of $2.45 to $2.55 per share on revenues of $780 to $788 million, compared to Reuters' estimate of $2.72 per share on revenues of $804.54 million.

Hormel Foods Corp. (HRL) shares fell 2.71 percent to $28.04 in post-market trading. The stock has a 52-week low of $25.87, a 52-week high of $30.70 and $7.59 billion in market capitalization.

General Growth Properties, Inc. (GGP) shares fell 1.62 percent to $19.99 in post-market trading. The company stock climbed nearly 10 percent in regular trading.

Sprint Nextel Corp. (S) shares declined 1.46 percent to $4.71 in post-market trading. The stock has a 52-week low of $2.10, a 52-week high of $5.49 and $14.34 billion in market capitalization.