Caterpillar Inc. said Friday it appointed Andrew Bonfield as chief financial officer effective Sept. 1, to succeed current CFO Brad Halverson, who will retire effective May 4. Shares of the heavy machinery maker were little changed in premarket trade. Halverson had previously announced plans to retire in August 2017. Bonfield was most recently Group CFO of U.K.-based gas and electric utility company National Grid PLC. Halverson made headlines last week when he said on Caterpillar's post-earnings conference call that first-quarter results were likely the "high watermark for the year, sending the stock tumbling. The stock had lost 6.6% since then through Thursday, while the Dow Jones Industrial Average has shed 519 points, or 2.1%.