The Pennsylvania Public Utility Commission today approved a $55-million electricity rate increase package for PPL Corp. of Allentown.

The amount, approved 3-1 by the commission, would raise a monthly $98 residential electric bill by $4, the commission said.

PPL called the increase "modest." It represents a 1.7 percent increase in the company's total revenue, PPL said. The change goes into effect Jan. 1.

The utility had requested a revenue increase totaling $83.6 million. But that request was challenged by groups including the state's Office of Consumer Advocate, The PPL Industrial Customers Alliance, and Pennsylvania's Office of Small Business Advocate.

The increase affects 1.2 million residential customers in Berks, Bucks, Carbon, Chester, Clinton, Columbia, Cumberland, Dauphin, Juniata, Lackawanna, Lancaster, Lebanon, Lehigh and Luzerne Counties.

Under terms of a Commonwealth Court ruling in an earlier PPL rate case, most of the new rate increase will be borne by residential customers - a fact that several PUC commissioners raised objections to.

"The allocation of the rate increase in this proceeding shocks the fundamental principle of gradualism," said chairman Wendell F. Holland. The commission said he was the lone dissenter in the decision.

PPL shares were down 29 cents, to $52.86 in midday trading on the New York Stock Exchange.