NEW YORK ( TheStreet) -- An internal JPMorgan Chase ( JPM) e-mail message describing a meeting involving CEO Jamie Dimon and Banco Santander ( STD) boss Emilio Botin offers a fascinating glimpse into the banking industry, and may also be worthy of scrutiny for antitrust reasons. The JPMorgan e-mail, sent on June 5, 2008, came to light recently in connection to litigation stemming from that company's acquisition of Washington Mutual from the Federal Deposit Insurance Corp. in September of that year in the biggest bank failure in the history of the American financial system. >>>>>Click here to see the JPMorgan e-mail. Written by Jose Cerezo, an investment banker at JPMorgan, the e-mail describes the two bank bosses and a Santander executive board member, Juan Inciarte, talking about several possible acquisitions of interest to both banks at the time, including WaMu, Suntrust ( STI), PNC Financial ( PNC), and Wachovia (which was eventually acquired by Wells Fargo ( WFC)). "It is important to have an open dialogue with them, as Santander would not pursue any of these opportunities if JPMorgan were to do the same (can't compete on price with JPMorgan for an acquisition in the USA). But Santander would probably hire JPMorgan as advisor if we are not going after them," Cerezo writes. The suggestion in the e-mail that the banks may be divvying up the market, or that Santander might reward JPMorgan with an advisory fee if it chose not to pursue a target of interest to both banks, is troubling, according to Ian Ayres, an economics and law professor at Yale University. "The email is very problematic. If I were in the Justice Department I'd immediately open an investigation to pursue this further," Ayres said.