CLEVELAND, Oct. 19 -- Cleveland-Cliffs told investors on Monday that it had just posted its strongest quarter in three years, and in the same release it said it is indefinitely idling the galvanizing lines at Stelco, the Canadian steelmaker it bought two years ago.

The announcement lands inside a fight. Ottawa has pressed Cliffs since early October over Stelco layoffs in Hamilton, and Industry Minister Melanie Joly said on Friday that the company must keep the jobs in Canada or face the prospect of selling its Canadian assets.

Lourenco Goncalves, Cliffs' chairman and chief executive, gave his reasons in the release. Stelco's third quarter was its "strongest quarter since we acquired the company two years ago," he said, because a better ...