Airlines operating at Pittsburgh International Airport are facing a big increase in rates and charges next year as flights continue to decline.

Per passenger costs will jump 48 percent, from $11.19 to $16.62, under the $88.9 million operating budget adopted today by the Allegheny County Airport Authority board.

Landing fees will increase from $2.49 to $3.36 per 1,000 pounds and terminal fees will jump from $110 to $149 per square foot. The biggest increase will be in ramp fees, which will go from $197.47 to $574.74 per linear foot.

Authority Executive Director Bradley D. Penrod said the increases were primarily the result of continuing cutbacks by US Airways, the dominant carrier. The number of passengers boarding flights next year is expected to drop from 4.75 million to 4.1 million.

Last year, the authority closed 27 gates and increased fees at the beginning of the year as a result of US Airways cutbacks, then reduced the fees in February after saving about $10 million by refinancing some debt. It will try refinancing another portion of the debt to provide a similar rate reduction.