In the days since American Express chairman Harvey Golub, attacked Visa and invited bankers to issue his company's cards and explore other types of alliances, the combatants have settled into a wary silence.

Mr. Golub dropped his bombshell at a credit card conference in Atlanta last week, but has kept a low profile since. "Until we have an actual deal," said American Express spokeswoman Gail Wasserman, "I don't know how much more detailed we can be."

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