CSX's decision came hours after it announced the appointment of Jim Foote as its new chief operating officer.

CSX has been undergoing a major overhaul under new Chief Executive Hunter Harrison. The 72-year-old railroading executive, famous for turning around Canadian railroads, was appointed in March to great investor fanfare.

But rapid-fire changes to operations and cost cuts, and ensuing service delays, have drawn ire from customers and scrutiny from rail regulators and raised questions about how long it could take for his "precision scheduled railroading" strategy to fully take root.

"The Board's action to expand the repurchase program demonstrates our confidence in CSX's long term future and ability to generate substantial free cash flow," Harrison said in a written statement.

Shareholders had been expecting to get more details on the railroad's operating strategy and, perhaps, on Harrison's succession plans, at the now-postponed Oct. 30 conference.

Foote is due to take on the responsibilities of current Chief Operating Officer Cindy Sanborn and Chief Sales and Marketing Officer Fredrik Eliasson, both of whom plan to resign effective Nov. 15, the Jacksonville, Florida-based company said on Wednesday.

(Reporting by Eric M. Johnson in Seattle; Editing by Phil Berlowitz)