Vale SA, the world’s largest iron-ore producer, gained the most...

Vale SA, the world’s largest iron-ore producer, gained the most in more than six years on speculation that miners will start easing a production glut that sent prices to 10-year lows.

Shares of Vale surged 9.8 percent, the most since December 2008, at the close in Sao Paulo on Wednesday. The stock was the best performer among 47 metals, mining and steel companies in the Bloomberg Industries aggregate index for the day.

“Vale is already adjusting iron-ore output to a more challenging market, and we see the first signs of this strategy,” Bradesco analysts led by Alan Glezer said in a research note, adding that the producer shut its Jangada plant “likely due to cost inefficiency.”