The Norwegian government has introduced an Air Passenger Tax, starting on 1st June 2016. The tax rate is 80 NOK (around €8.64, £6.59, US$9.67) per person and is charged for all passengers that are being transported between two Norwegian destinations or from a Norwegian airport to a destination outside Norway.
The tax payments shall be based on detailed statistical reports from the airline. Foreign airline companies without a fixed place of business in Norway ("foreign airlines") must be registered through a representative. The representative and the foreign airline will be jointly liable for the reporting and payment obligations.
There is more information in the press release from the government: http://norwaytoday.info/finance/norwegian-collects-air-passenger-tax/
KPMG in Norway can provide the representation service to foreign airlines.