MADISON, Wis. -- State regulators have formally approved a $12.9 million rate increase for Wisconsin Public Service Corporation.

That translates to about $2.75 more per month for residential customers. The utility originally asked for $14.4 million.

Regulators also approved an $18 million increase in WPSC electric rates.

But that was largely offset by credits the utility plans to give customers because fuel costs for 2009 were lower than expected. The net effect is about 50 cents more per month for residential customers and generally flat rates for industrial customers.

The utility originally had asked for a $49 million electric increase, but WPSC spokesman Kerry Spees said lower fuel costs for 2010 reduced the request.