Shareholders of Dow Chemical and DuPont have approved a $59 billion merger that will eventually lead to a planned split into three companies and would likely affect more than 8,000 fleet vehicles.

The merger, which is expected to close later this year, must still pass regulatory approvals.

DuPont's Andrea Krzyzanowski manages a U.S. fleet of about 4,990 vehicles for the Wilmington, Del., company, while Dow maintains about 3,500 vehicles. Dow's fleet isn't centrally managed by the Midland, Mich., company.

Shareholders have approved the merger of the two largest U.S. chemical makers, the companies announced July 20 in a joint statement. The merger was announced Dec. 11.

DuPont has appointed a "clean team" to conduct the initial discussions between executives and managers of the two companies. How this merger may affect the two fleet operations has yet to be determined.

Following the finalization of the merger, DowDuPont will pursue a plan to create three independent, publically traded companies, including an agriculture company, material science company, and specialty products company. The company will maintan dual headquarters in Midland and Wilmington.

"It is too preliminary to comment on broader impact at this time, but we expect to grow the Material Science business, by combining low-cost integration and innovation with expanded customer offerings in key growth sectors," said Jamie Ellis, a Dow spokesperson.