It is now a subsidiary of Kollektivtransportproduksjon, a municipal company responsible for operating public transport in Oslo.

As of 2005 the bus fleet consisted of: By the 1920s, the Oslo Tramway had grown to a series of lines spanning from the city center to new neighborhoods.

On 13 November 1927, Oslo Sporveier, who operated the city trams, started Line 18 between Alexander Kiellands plass and Loelvdalen.

The company had bought ten buses from Strømmens Værksted, each with room for 23 seated and 17 standing passengers.

They had Hall Scott gasoline engines with a power output of 48 kilowatts (64 hp), and stationed at Vålerenga Depot.

After a week, the line was further extended to Storgata, which was served by the tramway, thus allowing passengers to transfer.

Oslo Sporveier followed up with a serial delivery of ten units which were slightly smaller and had a capacity of 60 passengers.

[5] On 18 January 1931, the Bus Ring was established as an extension of Line 20 in both directions, so it ran from Frogner via Majorstuen, Sagene, Torshov, Rodeløkka, Grünerløkka, Kampen to Tøyen.

Being built out of aluminum, it weighed 5,080 kilograms (11,200 lb), allowing reduced fuel and rubber consumption.

Christened Flodhest (meaning hippopotamus), 70 units were serial produced from 1936 to 1939, and remained in service until 1958.

[6] In 1931, the company sent an application for concession to operate a trolleybus from the city limited on Trondheimsveien to Grorud.

[6] Oslo Sporveier argued that a trolleybus would give better service, but the application was rejected, as it was sufficient improvement to terminate Schøyen Bilcentraler's concession.

It returned to Oslo and was put into service on a new trolleybus route, Line 17 from Rodeløkka to Nordre Åsen, from 15 December 1940.

On 5 December 1943, Line 21, from Carl Berners plass to Skillebekk, was opened as a trolleybus, with 11 buses being used on the route.

The same year, the Norwegian resistance blew up the garage at Bjølsen, which was being used to manufacture parts for the German Messerschmitt Bf 109 aircraft.

[10] In 1948, Oslo Sporveier took over the bus routes operated by Wicktor Ruud to Riskløkka and Økernbråten.

[14] In November 1977, Oslo Sporveier bought De Blå Omnibusser and its 24 buses, which was based at Alnabru.

Each service ran once an hour in each direction, with clockwise and counter-clockwise routes running every half-hour.

From 27 March, a circle bus route was established from Tveita Station on the Furuset Line of the metro, along Sigrud Undsets vei.

[19] From 10 October 1991, the bus division started a service line for the elderly and disabled in the areas Haugerud, Tveita Oppsal, Bøler, Bogerud and Skullerud.

From 7 July 1992, Oslo Sporveier received two Ontario Orion II25 buses for these routes, which had experienced a 90% load factor.