Baltimore Gas & Electric Co. filed a request for a $96.1 million rate increase with the Maryland Public Service Commission yesterday that would add more than $3 to the average customer's monthly gas or electric bills.

BG&E officials said the increase, which would take effect next July, is the smallest the utility has requested in a full rate case in six years and its only rate-hike request in 17 months.

They estimated that the increase would raise the average customer's monthly electricity bill by $3.53 and the average gas heating customer's bill about $3.70 a month.

The increase would represent a 5.9 percent rise in annual operating revenues for the utility.

BG&E's filing includes a $142.6 million increase in the company's operating expenses, excluding fuel costs. BG&E officials said that increase would be partially offset by a $46.5 million reduction in the cost of fuels from switching from expensive imported oil to lower-cost coal at the Charles P. Crane Power Plant next spring.

BG&E has 855,203 heating customers and 510,753 gas customers in central Maryland, including all of Baltimore City and County, Anne Arundel and Howard counties, and parts of Carroll, Harford, Cecil, Calvert, Montgomery and Prince George's counties.