By Colin Kellaher 



  American Express Co. on Monday said it agreed to buy substantially all of online small-business lending platform Kabbage Inc. for an undisclosed amount. 


  The New York financial-services company said the deal expands its digital cash-flow-management offerings for small businesses. 


  Barron's earlier this month reported that Kabbage was weighing a sale, and that a person familiar with the matter said the fintech startup could sell for $750 million to $1 billion. 


  American Express said it will acquire Kabbage's team and its suite of financial-technology products, data platform and IP built for small businesses. The Atlanta firm's pre-existing loan portfolio isn't included in the agreement. 


  American Express said it expects to complete the acquisition later this year. 


  Write to Colin Kellaher at colin.kellaher@wsj.com