The top after-market NYSE gainers Wednesday were Pandora Media, LyondellBasell Industries, GenCorp, ING Group and Turquoise Hill Resources Ltd. The top after-market NYSE losers were Oxford Industries, Rogers Communication, Tim Hortons, Asbury Automotive Group and Bank of Nova Scotia.

Gainers

Pandora Media, Inc. (P) shares rallied 9.42 percent to $11.03 in post-market trading. The company reported the second quarter adjusted net profit of $622,000 or breakeven per share, down from $3.3 million or $0.02 per share in the same period last year and against analysts' estimate of a loss of $0.03 per share. The company currently expects that the fiscal 2013 revenues would be in a range of $425 to $432 million, up from its prior estimate of $420 to $427 million and also topped Reuters' estimate of $424.16 million revenue.

LyondellBasell Industries NV (LYB) shares surged 4.67 percent to $49.50 in post-market trading. The company will replace Sears Holdings Corp in the S&P 500 after the close of trading Tuesday, September 4.

GenCorp Inc. (GY) shares surged 3.07 percent to $9.39 in post-market trading. The stock has a 52-week low of $3.74, a 52-week high of $9.24 and $552.07 billion in market capitalization.

ING Group, N.V. (ING) shares gained 2.92 percent to $7.39 in post-market trading. The stock has a 52-week low of $5.51, a 52-week high of $10.43 and $27.29 billion in market capitalization.

Turquoise Hill Resources Ltd. (TRQ) shares rose 2.42 percent to $8.45 in post-market trading.

Losers

Oxford Industries, Inc. (OXM) shares slumped 8.83 percent to $48.02 in post-market trading as its third quarter earnings guidance fell short of expectations. The company expects the third quarter adjusted net profit to be in the range of $0.18 to $0.23 per share on revenues of $175 to $185 million that fell short of Reuters' estimate of $0.24 per share on revenues of $191.89 million.

Rogers Communication, Inc. (RCI) share plunged 2.97 percent to $39.65 in post-market trading. The stock has a 52-week low of $32.27, a 52-week high of $41.11 and $21.05 billion in market capitalization.

Tim Hortons Inc. (THI) shares fell 2.82 percent to $49.80 in post-market trading.

Asbury Automotive Group Inc. (ABG) shares declined 2.70 percent to $26.88 in post-market trading. The company stock surged nearly 3 percent in regular trading.

Bank of Nova Scotia (BNS) shares fell 2.66 percent to $52.72 in post-market trading. The stock was downgraded to a "neutral" rating from an "outperform" rating at Credit Suisse.