Dutch bank ABN Amro can proceed with its sale of U.S. unit LaSalle, the Dutch Supreme Court said, boosting the prospect that Barclays will succeed in its near $90 billion takeover bid for ABN. But a rival consortium led by Royal Bank of Scotland said it intended to make a revised offer for ABN Amro. "This offer will be on materially superior terms to Barclays' proposed offer and will not be conditional upon LaSalle remaining part of the ABN Amro group," RBS and its partners, Santander and Fortis, said late on Friday.