By Edward Taylor, Arno Schuetze and Alexander Hübner

The automaker has said it could list up to 25 percent of Traton in a deal expected to raise 5-6 billion euros ($5.7-$6.8 billion) and be Germany's biggest share offering this year.

The sources said the company remained on track to start the listing process before Easter, but could limit the number of shares sold if markets are roiled by Britain's planned departure from the European Union on March 29.

"We do not need to list 25 percent as a first step," one of the people said.

Volkswagen (VW) and Traton declined to comment.

VW is aiming to list Traton as part of its drive to create a global trucks business by integrating its MAN and Scania divisions.

Plans to formally initiate a public offering, known as an intention to float (ITF), are not expected until the second half of March, followed by the listing four weeks later, sources familiar with the discussions told Reuters.

Traton currently has 2.77 billion euros in bank liabilities and 3.22 billion euros in other loans and liabilities according to a company presentation published on Monday.

A flotation could give the business the resources to deepen its relationship with Navistar, a U.S. truck maker in which it currently owns a 16.85 percent stake.

JP Morgan, Goldman Sachs, Deutsche Bank and Citi have been hired as global coordinators for the listing.

Traton said on Monday its adjusted operating profit rose 13 percent to 1.7 billion euros last year thanks to a Brazilian market recovery, efficiency gains at MAN and a rise in vehicle deliveries.

The business forecast a return on sales of 6.5-7.5 percent for 2019, as well as a slight increase in revenue and vehicle deliveries, adding efficiency improvements and cost cutting at MAN would continue.

Traton's 2018 return on sales was 6.4 percent, up from 6 percent in 2017, while revenues rose 6 percent to 25.9 billion euros. That was helped by Volkswagen Caminhoes e Onibus, Traton's Brazilian arm, where a 22 percent jump in revenues fueled a return to an operating profit of 28 million euros.

Traton said it sold 233,000 vehicles of the MAN, Scania and Volkswagen Caminhoes e Onibus brands, 14 percent more than 2017.

"We remain right on track to become a global champion. As a group of strong brands, we create success for our customers and tap synergies together. We are ready to take the next steps," Traton CEO Andreas Renschler said.

(Reporting by Edward Taylor, Arno Schuetze and Alexander Huebner; Editing by Alexander Smith and Mark Potter)

By Edward Taylor, Arno Schuetze and Alexander Hübner