I would like to build openssh

64bit on solaris 10 U4 on a dual core opteron system

My issue is that at the link phase:

SunStudio/12/SUNWspro/bin/cc -V -o ssh ssh.o readconf.o clientloop.o
sshtty.o sshconnect.o sshconnect1.o sshconnect2.o -L. -Lopenbsd-
compat/ -L/usr/sfw/lib/amd64 -R/usr/sfw/lib/amd64 -L/usr/lib -R/usr/
lib -L/usr/sfw/lib/amd64 -lssh -lopenbsd-compat -lresolv -lcrypto -lrt
-lz -lsocket -lnsl
cc: Sun C 5.9 SunOS_i386 Patch 124868-01 2007/07/12
ld: Software Generation Utilities - Solaris Link Editors: 5.10-1.489
ld: fatal: file ssh.o: wrong ELF class: ELFCLASS64
ld: fatal: File processing errors. No output written to ssh

I need the SunStudio compilers as gcc on the system is 32 bit and will
nor build 64 bit binaries. S far as I can tell

ssh.o is a 64 bit object

file ssh.o
ssh.o: ELF 64-bit LSB relocatable AMD64 Version 1

so I am not sure what this is telling me. Has anyone succesfully built
openssh in 64bit mode on solaris?