Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
department [dɪˈpɑːtmənt] n (in shop) отде́л; (in university, school) отделе́ние; (POL) ве́домство, департа́мент
Department of Trade and Industry Министе́рство торго́вли и промы́шленности
that's not my department (fig) я не специали́ст в э́том де́ле
Department of State (US) Госуда́рственный департа́мент
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.