C167L.LIB not correctly linked

When setting USEDEXTONLY for my project, I get the following error during the linking process:

*** ERROR L127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  ?C_INITSECSTART
    MODULE:  START_V3.obj (?C_STARTUP)
*** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  ?C_INITSECSTART
    MODULE:  START_V3.obj (?C_STARTUP)
    ADDRESS: 80E6H
*** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  ?C_INITSECSTART
    MODULE:  START_V3.obj (?C_STARTUP)
    ADDRESS: 80EAH

To overcome the problem I added C167L.LIB manually to my project. Now the linker is invoked with

C:\KEIL\C166\BIN\L166.EXE START_V3.obj, Main.obj, C:\Keil\C166\lib\C167L.LIB TO [...]

but the problem still remains. As you can see from the list of included modules from the .M66-file, the necessary parts of the library are not linked into the output file:

INPUT MODULES INCLUDED:
  START_V3.obj (?C_STARTUP)
         COMMENT TYPE 128: A166 V5.30
  Main.obj (MAIN)
         COMMENT TYPE 128: C166 V6.10

What can I do to persuade the linker to link the required modules from C167L.LIB into the project?