Volkswagen AG’s heavy-vehicle division is open to a takeover of U.S. affiliate Navistar International Corp. as the German company seeks scale to compete with global leaders Daimler AG and Volvo AB.

Volkswagen Truck & Bus, which is changing its structure to access capital markets, might consider boosting its existing stake in Navistar, once any stock or debt sale is completed, Chief Financial Officer Matthias Gruendler said at a Munich press conference. Any purchase could be funded by parent Volkswagen and not depend share or bond proceeds gained by the truck unit, he said.

A takeover “would theoretically be possible,” Gruendler said, outlining a potential price tag of about “3 billion to 4 billion,” without specifying dollars or euros. While he declined to comment on a possible time frame for a deal, he said cooperation between the two manufacturers is developing “very well.”

Volkswagen bought just under 17 percent of Navistar in 2016 to gain a foothold in North America, where Daimler makes Freightliner vehicles and Volvo owns the Mack brand. Andreas Renschler, head of Volkswagen Truck & Bus, outlined global growth plans on Monday that included adding sales in China and sharing costs across its MAN, Scania and Brazilian VW commercial-vehicle operations through joint procurement and development of parts.

Capital-market preparations will take 12 months, and MAN’s Diesel & Turbo engine and Renk industrial-equipment units will be shifted from the commercial-vehicle division to parent Volkswagen, the executives said.

“This comprehensive project will accelerate the transformation of our company” into “a true global champion, and will quickly make it ready for the capital markets,” Renschler said at a press conference in Munich. He reiterated that no decision has been made on an initial public offering yet.

The revamp of the heavy-vehicle division, which Evercore ISI estimates has as much as 30 billion euros ($37 billion) in assets, marks the most significant structural shift so far for Volkswagen as the world’s biggest carmaker retools for massive change across its industry. The German manufacturer appointed Herbert Diess, head of its namesake auto brand, as its new chief executive officer last week, and he pledged to accelerate decision-making across the group to adapt to rapid shifts in technology and competition.

An IPO for the truck and bus unit “is just one of the options” the division is considering to gain financing, Renschler said in an interview, adding that another would be to sell bonds. “It’s ultimately a decision for our shareholders.”

VW Chairman Hans Dieter Poetsch told reporters on Friday the auto manufacturer will retain a controlling stake in the commercial-vehicle business and that a share sale might not happen until 2019, as it still requires final approval.