[clisp-list] unwanted new line

[<don...@is...>]

(setf list '("abc" "def" "qwe
rty
uiop" "zxc"))

(with-output-to-string (s)(loop for x in list do (format s "~s~c" x #\tab)))
"\"abc\"        \"def\"
\"qwe
rty
uiop\"  \"zxc\" "

Why is there an extra new line before the list element that contains
the newlines?
Is there some way to suppress it ?