The top after-market NYSE gainers Wednesday were Millennial Media, FleetCor Technologies, NQ Mobile, Dillard's, Orbitz Worldwide and MBIA, Inc. The top after-market NYSE losers were Medicis Pharmaceutical, Teekay Tankers, McEwen Mining, China Nepstar Chain Drugstore and ING Groep NV.

Gainers

Millennial Media, Inc. (MM) shares rallied 11.87 percent in post-market trading. The company reported the second quarter net loss of $2.2 million or $0.03 per share on revenues of $39.4 million, better than Reuters' estimate of loss of $0.05 per share on revenues of $38 million. Millennial Media also raised its full-year revenue guidance to a range of $176 to $179 million, up from its prior estimation of $173 to $176 million.

FleetCor Technologies, Inc. (FLT) shares climbed 10.76 percent to $40.65 in post-market trading after raising its full year guidance. The company currently expects fiscal 2012 earnings to be in the range of $2.74 to $2.78 per share, up from its prior estimate of $2.55 to $2.60 per share and above analysts' estimate of $2.58 per share.

NQ Mobile Inc. (NQ) shares surged 7.87 percent to $8.36 in post-market trading. The company expects that its third quarter revenue will be in a range of $24 to $25 million and full-year revenue will be $86 to $89 million compared to analysts' estimate of $23.34 revenue for the third quarter and $85.18 million for fiscal 2012.

Dillard's, Inc. (DDS) shares surged 6.47 percent to $74.86 in post-market trading. Its second quarter net profit surged to $31.0 million or $0.63 per share from $17.6 million or $0.32 per share in the same period a year ago.

Orbitz Worldwide, Inc. (OWW) shares gained 5.76 percent to $3.67 in post-market trading. The company stock slumped more than 25 percent in regular trading.

MBIA, Inc. (MBI) shares advanced 5.02 percent to $9.20 in post-market trading. The company reported the second quarter net income of $581 million or $2.98 per share, sharply higher from $137 billion or $0.68 per share in the same period last year.

Losers

Medicis Pharmaceutical Corp. (MRX) shares slumped 6.33 percent to $31.20 in post-market trading. The company reported the second quarter net income of $14.93 million or $0.24 per share, sharply lower from $28.78 million or $0.43 per in the same quarter a year-ago. MRX expects that its third quarter net profit will be in a range of $0.41 to $0.58 per share on revenues of $185 to $200 million compared to Reuters' estimate of $0.78 per share on revenues of $221.95 million.

Teekay Tankers Ltd. (TNK) shares plunged 5.12 percent to $4.08 in post-market trading. The company announced Wednesday that its Board of Directors had voted to declare a cash dividend of $0.11 per share for the quarter ending June 30, 2012, payable on August 27 to all shareholders of record on August 20, 2012.

McEwen Mining Inc. (MUX) shares fell 2.65 percent to $3.31 in post-market trading. The stock has a 52-week low of $1.96, a 52-week high of $6.49 and $910.82 million in market capitalization.

China Nepstar Chain Drugstore Ltd. (NPD) shares declined 2.38 percent to $2.05 in post-market trading.

ING Groep NV (ING) shares declined 2.01 percent to $6.82 in post-market trading. The stock has a 52-week low of $5.51, a 52-week high of $10.43 and $26.39 billion in market capitalization.