In a letter to companies that list their shares on the New York Stock Exchange, rival Nasdaq has dangled an intriguing carrot.

Nasdaq said it plans to lower the maximum listing fees currently paid by NYSE-listed companies to $450,000 from $500,000. Of course, the fee cut only goes into effect if Nasdaq succeeds in its plan to take over Big Board parent company NYSE Euronext and divvy it up with the Interncontinental Exchange.