Dec 16 (Reuters) - U.S. steelmaker Nucor ( NUE ) forecast fourth-quarter profit below

Wall Street estimates on Monday, citing a slump in earnings in their steel mills segment caused

by decreased volumes and lower average selling prices.

The company expects fourth-quarter earnings to be in a range of $0.55 to $0.65 per diluted

share, lower than analysts' estimates of $0.90 per share, according to data compiled by LSEG.

However, it expects earnings in its raw materials segment to increase year-over-year in the

fourth quarter.

Peer Steel Dynamics ( STLD ) also forecast its fourth-quarter earnings below Wall Street

estimates on Monday as the Indiana-based company sees lower realized steel prices and fall in

shipments.