Car-Rent.com compares the prices of well-known car rental companies in Portugal, including the following location: Porto Airport
Porto Airport is the airport of the port city of Porto, in the north of Portugal. In Portuguese the airport is called, Aeroporto Internacional Dr. Francisco de Sá Carneiro. The airport is named after a politician who was killed in a plane crash in 1980 while on his way to the airport. It was never clear if the plane crash was the result of an accident or a premeditated attack.
Porto Airport is designated by the aviation industry with the IATA code OPO and the ICAO code is LPPR. With regards to the Wikipedia article over Porto Airport, the airport has one take-off and landing runway.
At the time of writing this, there are six car rental companies who have offices situated at Porto Airport: Avis, Budget, Europcar, Hertz, National/Alamo and Sixt.
The airport's official website can be found via the following address link: Porto Airport