TAKING THE PULSE: With natural gas prices hovering near 10-year lows, investors have fled coal companies, pushing the Dow Jones U.S. Coal Index down by more than half in the past year.

To Moody's Investors Service, the gas glut heralds a sea change. "Coal will find it increasingly difficult to compete with gas as a power source over the next decade," Moody's analyst Jim Hempstead said this month, as the rating firm projected a wide shift to exports. Demand from Asia is still high.

Others think the outlook isn't quite so dire. Analysts at FBR Capital Markets believe that most power plants capable of switching to natural gas have already done so. Some coal producers are cutting their output, which could raise prices down the line.

This month marks the two-year anniversary of an accident that killed 29 miners at the Massey Energy Co.'s Upper Big Branch mine in West Virginia--the worst U.S. mining disaster in four decades.

 
   COMPANIES TO WATCH: 
 
   Peabody Energy Corp. (BTU) - reports April 19

Wall Street Expectations: Analysts surveyed by Thomson Reuters expect the company to earn 54 cents a share on revenue of $2.09 billion. It posted a profit of 65 cents a share, or 67 cents excluding tax-related costs, a year earlier on revenue of $1.74 billion.

Key Issues: The largest U.S. coal producer by output, Peabody has aggressively expanded its footprint in Asia in an effort to capitalize on strong demand in China and India. To that end, the company acquired Australian coal-mining company Macarthur Coal Ltd. last year in a $5.05 billion deal expected to boost the company's production of metallurgical coal, which is used by steelmakers. But Peabody's chief executive warned early this year that Macarthur mines weren't yet up to snuff, and would require costly repairs and upgrades. After floods in Queensland halted port and rail movement and restricted underground access, Peabody warned that its quarterly earnings would fall on the low end of its earlier downbeat projections.

 
   Arch Coal Inc. (ACI) - report tentatively scheduled for April 24

Wall Street Expectations: The company is expected to post income of 20 cents a share on revenue of $1.13 billion. A year earlier, it posted a profit of 34 cents a share, or 36 cents excluding acquisition-related costs and other one-time items, on revenue of $873 million.

Key Issues: Like other coal companies, Arch has said it would cut production this year. With an eye on ratcheting up exports, the company has arranged for additional port capacity in the U.S. and Canada, and opened offices in Singapore and London. Its $3.5 billion acquisition in June of International Coal Group made it the second-largest U.S. producer of metallurgical coal.

 
   Consol Energy Inc. (CNX) - reports April 26

Wall Street Expectations: The coal and natural gas company is expected to earn 59 cents a share on revenue of $1.38 billion. A year earlier, the company reported earnings of 84 cents a share on $1.47 billion in revenue.

Key Issues: Consol Energy has seen soaring profits over recent quarters, mostly on coal exports, at the same time as it has bolstered its natural gas partnerships. In the new year, Consol Energy said it is trimming its investments in its Marcellus Shale assets, as natural gas prices continued to drop. The company last month idled its Buchanan longwall mine operations in southwest Virginia for an indefinite period, a move that UBS interpreted as "a shot across the bow" to Asian buyers who are pressing the company to accept lower prices on U.S. metallurgical coal.

 
   Alpha Natural Resources Inc. (ANR) - report tentatively scheduled for May 3

Wall Street Expectations: Analysts are expecting the company to post a loss of 4 cents a share, as it brings in revenue of $1.92 billion. Alpha posted a year-earlier profit of 41 cents a share, or 65 cents excluding acquisition costs and health-care charges, on revenue of $1.13 billion.

Key Issues: Alpha's acquisition last year of Massey Energy Co. has so far proved to be a boon and a curse. Revenue doubled last quarter on Massey's legacy of metallurgical coal. But Alpha swung to a surprise loss in the period on write-downs, as it also inherited the higher costs of mining this coal, as well as litigation expenses related to the 2010 disaster at Upper Big Branch. Alpha in February said it would idle mines in Kentucky and West Virginia and reduce the year's shipments by 4 million tons, citing a combination of pressures from gas prices, federal regulations and weak demand. Moody's Investors Service responded by lowering its outlook on the company, pointing to the slowing growth rate of steel production in China, among other things.

(The Thomson Reuters financial estimates and year-earlier figures may not be comparable due to one-time items and other adjustments.)

-By Kristin Jones, Dow Jones Newswires; 212-416-2208; kristin.jones@dowjones.com