Unable to set EVENT parameter in SPFILE

Hi all,

I am trying to set few Event parameters in SPFILE using the command below.

ALTER SYSTEM SET EVENT='10027 trace name context forever, level 1' SCOPE=SPFILE;

But each time i set a new event parameter, the old one is getting replaced by the new one in the SPFILE instead of the new one getting Appended below the first.

Any help is appreciated.

Regards,

Sandeep.