The top after-market NYSE gainers Monday were Blyth, Inc, Stage Stores, Heckmann Corp, Manitowoc Co and Manchester United plc. The top after-market NYSE losers were Fifth & Pacific Companies, Core Laboratories, Kronos Worldwide, Genesis Energy and Ship Finance International Ltd.

Gainers

Blyth, Inc. (BTH) shares surged 4.78 percent to $28.05 in post-market trading. The company announced Monday that along with the founders of the ViSalus business -- Ryan Blair, Blake Mallen and Nick Sarnicola -- it had reached an agreement, in principle, to defer the final closing of Blyth's purchase of the ViSalus business until April 2014, put in place new employment agreements and implement an equity incentive program for members of the ViSalus management team.

Stage Stores, Inc. (SSI) shares surged 2.54 percent to $21.80 in post-market trading after announcing that comparable store sales for the September period increased 11.1 percent.

Heckmann Corp. (HEK) shares gained 2.38 percent to $4.30 in post-market trading. The stock has a 52-week low of $2.60, a 52-week high of $7.05 and $637.17 million in market capitalization.

Manitowoc Co, Inc. (MTW) shares rose 2.37 percent to $13.66 in post-market trading. The stock has a 52-week low of $5.76, a 52-week high of $16.97 and $1.76 billion in market capitalization.

Manchester United Plc. (MANU) shares advanced 1.64 percent to $12.76 in post-market trading. The stock has a 52-week low of $12.00, a 52-week high of $15.27 and $2.07 billion in market capitalization.

Losers

Fifth & Pacific Companies, Inc. (FNP) shares slumped 12.37 percent to $11.19 in post-market trading after lowering its adjusted EBITDA guidance for fiscal 2012. The company expects 2012 adjusted EBITDA to be in a range of $100 to $115 million, down from its prior estimation of $125 to $140 million.

Core Laboratories N.V. (CLB) shares plunged 9.96 percent to $108.61 in post-market trading after the company lowered its third quarter earnings guidance. The company expects the third quarter net profit to be in a range of $1.09 to $1.13 per share on revenues of $240 to $245 million, down from its prior estimate of $1.17 to $1.25 per share on revenues of $250 to $260 million and also fell short of Reuters’ estimate of $1.22 per share on revenues of $255.87 million.

Kronos Worldwide Inc. (KRO) shares plunged 6.77 percent to $13.77 in post-market trading. The company announced that it expected to report net sales for the third quarter of 2012 of between $480 million to $495 million, down from $5 48.0 million in the same period last year.

Genesis Energy, L.P. (GEL) shares fell 5.12 percent to $32.79 in post-market trading. The company announced the commencement of an underwritten secondary public offering of 6,000,000 common units representing limited partner interests by Quintana Capital Group II, L.P. and some of its affiliates and other selling unit holders. 

Ship Finance International Ltd. (SFL) fell 5.06 percent to $15.19 in post-market trading after announcing an underwritten public offering of 6,000,000 common shares.