NEW YORK (Associated Press) - Shares of drybulk shippers sank with the broader market Monday, but a Jefferies & Co. analyst said falling spot charter rates could be heading up again.

Drybulk vessels transport materials such as grain, coal and iron ore to global markets, and rates for those vessels have been on a steady decline since peaking last spring. More recently, demand for iron ore fell off in China after the government forced steel plants and construction sites to close to cut emissions and smog.

Analyst Douglas Mavrinac said Chinese plants are firing up again and construction activity should rebound soon. "We believe dry bulk shipping demand and correspondingly dry bulk shipping spot charter rates are likely to rebound as well providing a positive catalyst for the dry bulk shipping shares," he wrote in a note to investors.

The daily spot rate for a medium-sized vessel is about $43,000, up $244 from Friday, according to the Baltic Dry Index.

In afternoon trading, Dryships fell $3.28, or 6 percent, to $51.87. Eagle Bulk Shipping lost $1.32, or 5.7 percent, at $21.94. Diana Shipping dropped 87 cents, or 3.5 percent, to $23.91. Overseas Shipholding fell 80 cents to $67.45.