Standard & Poor's put Massey Energy Co.'s credit rating on watch Tuesday because of uncertainty over the coal company, including reports that it could be sold.
S&P rates Massey's credit at "BB-minus." By putting Massey on watch, the agency could raise, lower or leave its ratings unchanged after it reviews the situation.
The Wall Street Journal reported that the Richmond, Va., company has formed a committee to study options including a sale.
S&P analyst Marie Shmaruk said Massey could become riskier if it makes a debt-financed acquisition or is the object of a leveraged buyout, but could look better with an acquisition that expands its geographic reach.
The company is also dealing with fallout from an explosion this year at one of its mines in West Virginia that killed 29 miners.
Massey shares rose $1.60, or 4.5 percent, to $37.16 in afternoon trading.