The checks on all arriving ferry passengers arriving from Denmark, Sweden and Germany will now remain in place until February 11th, 2017.
Justice Minister Anders Anundsen (FRP) made the formal decision on Friday after receiving a final green light from the European Commission.
“Although the number of asylum seekers arriving has been low throughout the year, there is still great uncertainty about the number of people who want to seek residence in Norway. Therefore it is important for the government to maintain the temporary border controls,” ministry spokesman Ove Andre Vanebo said.
Norway's border control measures were introduced in November 2015 and have since been extended several times. The most six-month extension was was due to expire on Saturday.
In addition to Norway, Denmark, Sweden, Germany and Austria have all introduced temporary controls in the wake of last year's refugee crisis.
The European Commission has given all five countries approval to extend the measures for another three months. The commission requires regular reports from Norway about the results of its border controls.
The latest report was submitted on October 17th and showed that a total of 53 people had been refused entry into Norway since the measures were introduced. Additionally, a total of 30 people applied for asylum upon arrival.
EU wants free movement within the Schengen area and therefore wants countries to do away with the controls, but has accept that they continue until further notice because Greece has not yet fully control the union's outer borders.