Combine, Merge, Concatenate

Dear pgsql users,

I have a problem, which is quite hard to solve it in Perl (for me, of
course). I have to tables, which looks like

First Table:

1|001|002|003
2|006|04|002

Second Table:

001|text1|text2|text3
002|text6|text1|text2

Now I would like to concatenate this two tables into new table:

Third Table:

1|text1|text2|text3|text6 *
2|etc

*Notes; key=1 from first table; substitute 001 from first table with
text1|text2|text3 and 002 with text6 etc...

Is that possible in pgsql?

Thanks in advance for any notes and suggestions,

Cheers, Andre