WM 46 on HPUX how to do we allocate more memory

We need to run WM release 4.6 on HP-UX PA-RISC with 64 bit JDK version to be able to allocate more memory. There seems to be an incompatibility with the JCO version in WM 4.6. We don’t find any 64 bit JCO libraries available for HP-UX PA-RISC architecture. What can we do to resolve this problem?

Java Version (46.0)
Java Vendor Hewlett-Packard Co.