SQL Anywhere 17

I have a view which contains this JOIN condition:

JOIN s1_release
LEFT OUTER JOIN gsr_release_load_balance
ON s1_release.contract_nbr = gsr_release_load_balance.contract_nbr
AND s1_release.release_nbr = gsr_release_load_balance.release_nbr
ON s1_contract.contract_nbr = s1_release.contract_nbr

Produces this error:
Could not execute statement.
Syntax error near 'ON' on line 208
SQLCODE=-131, ODBC3 State="42000"
Line 208

This SQL has been ported from Oracle 11g and runs with no errors in an Oracle environment.

"gsr_release_load_balance" is a view
"s1_contract" is a table, contract_nbr is a primary key
s1_release is a table, release_nbr is part of a primary key

Can someone provide the SQL syntax SQL Anywhere is looking for??

Thanks
Murray