Compiler not producing OBJ files

Using uVision, I'm not getting .obj files produced by C51. A51 produces .obj files OK in the same project. The example projects do produce .obj files, so the cause is likely project settings. A .LST file contains:

NO OBJECT MODULE REQUESTED

; COMPILER INVOKED BY:
; C:\Program Files\Keil\C51\BIN\C51.EXE BANK2.C LARGE OPTIMIZE(SIZE) BROWSE NOINTPROMOTE DEFINE(RAA_Limits=0) DEBUG OBJECTEXTEND OBJECT(.\Obj\BANK2.obj)

Thanks.