Error The text "*" is unexpected

I get a following error when i am porting to AIX

"The text "*" is unexpected"

Code:

##Sample code ##
class A
{
...

}

class B
{
friend class A;
public:
  B(A*& a); // <<--- Error (The text "*" is unexpected)
....

}

any idea why such error is reported by /usr/vacpp/bin/xlC_r compiler

thnks and regards,
kaustubh