Volkswagen AG tightened the price range for the share sale of the Traton SE truck unit to the lower end of an initial target to raise as much as 1.6 billion euros ($1.8 billion).

The world’s biggest carmaker is offering shares at 27 euros to 28 euros apiece, according to a term sheet seen by Bloomberg News. It initially targeted a range of between 27 euros and 33 euros apiece for a stake sale of as much as 11.5% in...