The Board of Selectmen on Tuesday unanimously approved a 40 percent increase in ambulance rates, the second such increase in two years. The base rate, not including additional charges such as mileage, will now be $1,048.45 for emergency service with basic life support, and $1,245.05 for emergency service with advanced life support. With the same vote, the board also raised fees for permits issued through the Fire Department. Fire Chief James Wright said that in both cases, the cost of doing business is driving the increases. The fee for an oil burner inspection, for example, does not cover the cost of overtime necessary for an employee to do the inspection. That fee will rise to $40 from $10. Wright told the board the new ambulance rates will put Sharon “on the higher end” in the region, but he expects other communities will be raising rates.