Fund manager Swedbank Robur on Thursday said it thinks the offer of 200 kronor ($30.62) per Scania share is reasonable.
Europe's biggest auto manufacturer said late February it wants to purchase the 37.4 percent of Scania it doesn't already own. Swedish pension fund AP4 and the Skandia Liv financial group have previously said they won't accept the bid.
With the acceptance from Swedbank Robur it will be more difficult for the naysayers to get the 10 percent backing they need to block the offer, which expires on Friday.
Scania shares rose by 7.5 percent to 186 kronor in Stockholm.