The top aftermarket NYSE gainers Thursday were: Sony Corp, PerkinElmer, Genworth Financial, Covanta Holding, Neustar, Iamgold Corp, Investment Technology Group, Netsuite and Weyerhaeuser Co.

Sony Corp. (SNE) shares climbed 8.19 percent to $18.49 in post market trading session. The company stock plunged more than 6 percent in regular trading session after reporting a third quarter net loss of ¥159 billion or ¥158.40 per share compared to net profit of ¥ 72.3 billion or ¥ 71.96 per shares in the same quarter last year.

PerkinElmer, Inc. (PKI) shares surged 6.89 percent to $26.39 in post market trading session after reporting fiscal 2012 earnings guidance above analysts' estimation. For fiscal 2012, the company expects earnings to be in a range of $1.98 to $2.04 per share and against analysts' estimation expectation of $1.92 per share. The company also reported fourth quarter adjusted net income of $0.62 per share compared to $0.45 per share in the same quarter last year and against analysts' estimation of $0.51 per share.

Genworth Financial Inc. (GNW) shares surged 6.09 percent to $8.53 in post market trading session. The company swung to fourth quarter net profit of $107 million or $0.22 per share compared to net loss of $161 million or $0.33 per share in the same quarter last year.

Covanta Holding Corp. (CVA) shares gained 5.94 percent to $15.34 in post market trading session. The stock has a 52-week low of $12.87, a 52-week high of $17.78 and $1.99 billion in market capitalization.

Neustar, Inc. (NSR) shares advanced 4.9 percent to $38.50 in post market trading session. The company reported fourth quarter adjusted net income of 37.0 million or $0.51 per share compared to $34.8 million or $0.46 per share in the same quarter a year-ago and against analysts' estimation of $0.35 per share.

Iamgold Corp. (IAG) shares gained 4.42 percent to $18.18 in post market trading session. The stock has a 52-week low of $14.69, a 52-week high of $23.88 and $6.54 billion in market capitalization.

Investment Technology Group, Inc. (ITG) shares gained 4.04 percent to $11.07 in post market trading session. The company stock plunged more nearly 4 percent in regular trading session after analysts' at JPMorgan Chase lowered price target on shares of ITG to $13.00.

Netsuite Inc. (N) shares advanced 3.97 percent to $46.12 in post market trading session after gaining more than 4 percent in regular session. The company reported fourth quarter adjusted net income of $3.4 million or $0.05 per share compared to $2.8 million or $0.04 per share in the same quarter a year-ago and against analysts' estimation of $0.04 per share.

Weyerhaeuser Co. (WY) shares advanced 3.28 percent to $20.80 in post market trading session.