--multifile produces no output file

Hello,

I am stumbled on use of the --multifile option of armcc.
I need it to build a large application image that would not fit the chip otherwise (a few hundreds of bytes gained from optimizations matter)

Instead of build from Keil, I made a batch script (based on generated by the IDE) with a single-pass compilation of all sources.

The problem is that for final linking I get no the result of the compilation.

In the simplest form, with just two files the build script is like this:

armcc -c -c99 --cpu Cortex-M0 --li -g -O3 --apcs=interwork --split_sections ^
-I ..\ARM\CMSIS\Include ^
-I ..\nrf51822\Include ^
-I Common ^
-I Main ^
--gnu --bss_threshold=0 ^
-D__MICROLIB ^
-D__UVISION_VERSION=525 ^
--info=totals ^
--list ^
--multifile ^
--omf_browse .\app_multifile.crf ^
Main\main.c ^
Startup\system_nrf51.c ^
-o "./multi_app.o"

if either main.c or system_nrf51.c is left, then the compilation produces the output file.
2+ source files give no such result.

I can see that other files are generated (.crf, .lst) and all sources are really built - it takes long time for my 30+ sources and warnings/errors are reported (if introduced to the source). I'd expect the result appearing in the current directory, and it cannot be found anywhere.

What am I missing?

BR, Oleksandr