I've now spent some time on this one as I have seen the term but never had to actually translate it, but may well do in future. In some texts it seems to be synonymous with "kostnadssenter", e.g. "Kostnadsobjekt er vanligvis kostnadssted (ansvarssted) eller produkt/tjeneste. ", and after checking out how "ansvarssted" is used, I really can't see how it can be anything else than "cost centre". Here's some useful refs.

1. cost centre. The area of an organization for which costs are collected for the purposes of cost ascertainment, planning, decision making, and control. Cost centres are determined by individual organizations; they may be based on a function, department, section, individual, or any group of these. Cost centres are of two main types: production cost centres in an organization are those concerned with making a product, while service cost centres provide a service (such as stores, boilerhouse, or canteen) to other parts of the organization."

2. The first two sections (AB-1-) identify the School ledgers:

■GS-1- = General School (includes MSL funds)
■GR-1- = Research funds
■GH-1- = Residences (term-time/non-commercial activity)
■GL-1- = Residences (vacation/commercial activity)
■GG-1- = International Growth Centre
The next two sections (CDE-2345-) identify the cost centre (which department or research grant etc.). The first three characters normally identify the department or division, the next four characters identify the sub-unit;


--------------------------------------------------
Note added at 10 hrs (2009-11-18 07:08:15 GMT)
--------------------------------------------------

Here's another good explanation of cost centre: http://www.sharecom.ca/manuals/glcap/costcen.html

--------------------------------------------------
Note added at 21 hrs (2009-11-18 18:29:06 GMT)
--------------------------------------------------

If there is agreement that "ansvarssted" is the same thing as "kostnadssted", then "cost pool" is an alternative term.
"Kostnadsted (Cost pool) er en gruppering av individuelle kostnadsposter. Fordelingsnøkkel (Cost allocation base) er en faktor som brukes som nevner i fordelingen av indirekte kostnader ut på de enkelte kostnadssteder." (Wikipedia)