AMEREN CORP. $40 (New York symbol AEE; Income Portfolio, Utilities sector; Shares outstanding: 209.5 million; Market cap: $8.4 billion; WSSF Rating: Average) provides electricity and natural gas to customers in Illinois and Missouri. The floods in the Midwest had little effect on Ameren. However, the company needs to spend about $1 billion in the next two years to upgrade some of its plants. About half of that will go to improving the environmental performance of its coal-fired power plants (coal accounts for 85% of its fuel needs). Ameren will probably recover most of these expenses through higher rates. Meanwhile, in the three months ended March 31, 2008, the company earned $0.64 a share (total $134 million) before one-time costs. That’s 8.6% less than the $0.70 a share ($145 million) it earned in the year-earlier quarter, mainly due to higher fuel costs. Revenue rose 5.0%, to $2.1 billion from $2.0 billion. Ameren trades at 12.9 times its forecast 2008 earnings of $3.10 a share. The $2.54 dividend yields 6.4%. Ameren is a buy.