Shares of lumber supply company Stella-Jones (SJ.TO) plunged Monday morning after the company announced a profit warning late Friday. 

The company says it expects fourth-quarter sales to fall to between $340-342 million, compared with sales of $357.5 million in the same period last year. Operating income is expected to drop to between $27-29 million compared with $48.3 million a year ago.

Stella-Jones attributed the warning to a drop in railway tie demand at the end of the year.

The company said in a press release it expects consolidated 2016 sales will grow 18 per cent to about $1.84 billion; with operating income coming in at between $232-234 million, compared to $220.1 million in 2015.