BUENOS AIRES, July 30 (Reuters) - A last-ditch plan for Argentine commercial banks to buy out the non-performing debt held by hedge funds and avert a default collapsed on Wednesday, a senior banking executive and a second source from the financial market said.

"It all fell through," said the banking executive.

(Reporting by Eliana Raszewski; Writing by Richard Lough; Editing by Lisa Shumaker)