The top after-market NYSE losers on Tuesday are: LDK Solar, Nalco Holding, Chicago Bridge & Iron, Ritchie Bros, STMicroelectronics, CB Richard Ellis, FMC Technologies, Cobalt International Energy, Red Hat and Western Union.

LDK Solar Co. Ltd. (NYSE:LDK) shares plunged 4.99 percent to $10.85 in post market trading session as the company cut its first quarter revenue outlook. LDK Solar lowered its first quarter 2011 revenue outlook to the range of $745 million to $755 million from its earlier estimation of $800 million to $850 million range, while analysts’ estimates revenue of $820.09 million for the first quarter.

Nalco Holding Co. (NYSE:NLC) shares declined 3.74 percent to $27 in aftermarket trading session. The company reported first quarter net income of $117 million or $0.84 per share compared to $25 million or $0.18 per share in the same quarter last year.

Chicago Bridge & Iron Co N.V. (NYSE:CBI) shares declined 3.44 percent to $39.32 in post market trading session. The company reported first quarter net income of $50.5 million or $0.50 per share, compared to $42.2 million or $0.42 per share in the same quarter last year.

Ritchie Bros. Auctioneers (NYSE:RBA) shares declined 2.99 percent to $29 in aftermarket trading session.

STMicroelectronics N.V. (NYSE:STM) shares declined 2.65 percent to $12.10 in post market trading session. The company reported first quarter net income of $175 million or $0.20 per share compared to $62 million or $0.07 per share in the same quarter last year.

CB Richard Ellis Group Inc. (NYSE:CBG) shares declined 2.28 percent to $27.90 in post market trading session. The company swung to first quarter profit of $34.37 million or $0.11 per share compared to a net loss of $6.63 million or $0.02 per share in the same quarter last year.

FMC Technologies, Inc. (NYSE:FTI) shares declined 2.23 percent to $47 in aftermarket trading session. The company reported first quarter net income of $85.2 million or $0.35 per share compared to $99.0 million or $0.40 per share in the same quarter last year.

Cobalt International Energy, Inc. (NYSE:CIE) shares declined 1.96 percent to $13.79 in aftermarket trading session. The company stock advanced 2.25 percent in regular trading session after Jefferies boosted their price target on shares of Cobalt International from $16.50 to $19.50.

Red Hat, Inc. (NYSE:RHT) shares declined1.96 percent to $45.57 in post market trading session.

Western Union Co. (NYSE:WU) shares declined 1.95 percent to $21.11 in aftermarket trading session. The company reported first quarter net income of $210.2 million or $0.32 per share compared to $207.9 million or $0.30 per share in the same quarter last year.

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