Nucor Corp. is encouraging the U.S. senators in the 23 states in which it operates to reject a climate-change bill passed by the House of Representatives.

The House approved the Waxman-Markey climate-change bill by a three-vote margin.

Steel producers in particular, and manufacturers in general, are opposed to the bill on many fronts, notably their belief that, as Nucor put it, the bill if enacted would have far-reaching...