* VW Truck & Bus says no decision has been made about IPO
* Says immediate goal is to reach capital markets readiness
* Manager Magazin says 25 pct stake to be listed in summer 2019 (Adds VW comment, further quotes from magazine interview)
FRANKFURT, June 21 (Reuters) - Proceeds of more than 6 billion euros ($6.9 bln) would flow to parent Volkswagen AG if it decides to list its truck and bus subsidiary, the division's chief executive told Manager Magazin as he set out the company's ambitions.
Manager Magazin said a listing of around 25 percent was being planned for summer 2019.
Wolfsburg-based VW has plans to build a global trucks business by integrating its MAN and Scania divisions and building its stake in U.S. truck maker Navistar to challenge rivals Daimler and Volvo.
Volkswagen has said it is considering a listing or partial listing of the division but has ruled out any listing in 2018.
"First of all the supervisory board of Volkswagen AG would need to formally approve an initial public offering," the division's chief executive Andreas Renschler was quoted telling the monthly German Manager Magazin.
"Nothing is decided, but the proceeds would flow to our shareholder," he said.
A spokeswoman for VW Truck & Bus confirmed to Reuters that no decision had yet been taken about the timing and size of a separate stock market listing.
Volkswagen Truck & Bus, which will be renamed Traton, will convert into a Societas Europaea in the fall, paving the way for a possible listing, Renschler told Manager Magazin.
By listing on the stock market, further expansion would be easier, thanks to new refinancing possibilities Renschler went on to say.
When asked whether VW Truck & Bus could raise up to 6 billion euros with a listing, Renschler told the magazine: "It could also be more."
A flotation could allow Volkswagen Truck & Bus to build a war chest to buy out Navistar completely, a U.S. truck maker in which it already owns 16.85 percent.
Regulatory filings by the U.S. truck maker from April showed that Volkswagen could take full control.(bit.ly/2H95QNY)
Asked whether VW Truck & Bus could buy out Navistar, Renschler said: "We only said that we think this is a sensible option, but never commented on when we will do this. Our strategic projects with Navistar are working well even without having a majority."
Asked whether Volkswagen Truck & Bus would consider increasing its 25 percent stake in Sinotruk, Renschler told the magazine: "Sinotruk is a very successful company, it has developed in a fantastic way in the past ten years. This is why we are discussing ways to develop our relationship with Sinotruk further." ($1 = 0.8668 euros) (Reporting by Edward Taylor Editing by Douglas Busvine and Elaine Hardcastle)