American Express to Buy Back Stock: The travel and financial services firm plans to repurchase up to 40 million of its shares, valued at nearly $1.4 billion at current market prices. The company said the stock purchases will be spread over the next two to three years. The buyback represents 8% of the 496 million common shares outstanding at the end of February. The New York-based company also announced its regular quarterly dividend of 22.5 cents a share, which is unchanged, payable May 10 to shareholders of record on April 7. American Express shares rose $1.25 to $35.25.