See http://www.utf8-chartable.de/unicode-utf8-table.pl
Unicode code point = U+039B
character = Λ
UTF-8 (hex.) = ce 9b
$ echo -e "\xCE\x9B" Λ
If the problem is remote only, likely that "echo" don't undeerstand the "\u039B" escape. Please note that "\u" is not reported as escape sequence in echo coreutils manuals. nor in POSIX
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html
To check it
$ echo -ne "\xce\xbb" |od -x 0000000 bbce 0000002 $ echo -ne "\u03bb" |od -x 0000000 bbce 0000002