Chrysler is reluctantly preparing for an initial public offering (IPO) of shares owned by the United Auto Workers (UAW) trust after failing to reach an agreement on the value of the stock with the trust. Chrysler shares haven’t been publicly traded since 1998, when the company merged with Daimler AG who is now a majority owner of Italian automaker Fiat SpA.

Sergio Marchionne, the CEO of both Fiat and Chrysler, has made it clear to the UAW that he wants to buy up shares and combine Fiat and Chrysler, but the two sides have been unable to agree on an IPO price. The trust has set the value of the stake at $4.27 billion US while Fiat says it is only worth $1.75 billion.

At the request of the trust, Chrysler filed the IPO paperwork with the U.S. Securities and Exchange Commission late Monday. Chrysler emphasized that the shares might never be publicly sold. The two sides could still reach an agreement on a price before the IPO us decided. Bankers and analysts view the filing as a move by the UAW trust to extract a better offer from Fiat and say that an IPO will most likely never take place.

Chrysler did not say how many shares will be offered in the sale. The UAW trust fund intends to use the proceeds to pay for medical benefits for blue-collar Chrysler retirees.