create or replace for aggregate function

Hi,

Is there an equivalent to
CREATE OR REPLACE FUNCTION FOO ...

for
CREATE AGGREGATE FOO ...

I have searched in TFM (as in RTFM) but can't seem to see it...

This is version 7.3.2 and I did not need to worry about it in 7.2.1, the
existing scripts worked differently I guess..

TIA

Coby Beck