Bank of America Corp. CEO Kenneth Lewis said his company’s deal to buy ABN AMRO Holding NV’s LaSalle Bank was “ironclad,” despite a Dutch court ruling that was intended to halt the $21 billion purchase, Reuters reported

Bank of America’s purchase of Chicago-based LaSalle was announced in April, when ABN AMRO accepted an $84 billion takeover bid from Britain’s Barclays plc that was conditional on the sale of LaSalle.

“We have an ironclad contract, and we expect to execute it,” Lewis said.

Since the Bank of America’s LaSalle deal was announced, the Royal Bank of Scotland Group Plc, Spain’s Banco Santander Central Hispano and Dutch-Belgian group Fortis made a $95 billion bid for ABN AMBRO that does not assume a LaSalle spinoff.

Last month, a Dutch commercial court ruled in favor of a petition by some ABN AMBRO investors to stop the LaSalle deal. Bank of America appealed this ruling to the Dutch Supreme Court earlier this month.

The Dutch Supreme Court is expected to decide this month or in early July whether ABN AMBRO can move forward with the LaSalle sale.