nohup psql does not read .pgpass

Hello!

Can you, please, help me determinate why psql does not read
the ~/.pgpass file when used with nohup?

echo 'select 1+1' >one.sql
psql -a --file=one.sql db    # works
time psql -a --file=one.sql db    # works
nohup psql -a --file=one.sql db    # asks for password

Environment variables are same
env >e
nohup env >ne
diff e ne
26c26
< _=/bin/env
---
> _=/usr/bin/nohup

psql --version
psql (PostgreSQL) 9.4.0
nohup --version
nohup (GNU coreutils) 8.4
cat /etc/system-release
CentOS release 6.6 (Final)

I have read and searched
http://www.postgresql.org/docs/9.4/static/app-psql.html
http://www.postgresql.org/docs/9.4/static/libpq-pgpass.html
but did not find any indices.

Regards
Hans Ginzel