Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
diversify [daɪˈvəːsɪfaɪ] vi разнообра́зить*(impf) (COMM) расширя́ть (расши́рить perf) вы́бор
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.