MILAN (Reuters) - Italian carmaker Fiat said on Thursday it planned to exercise a call option to buy around 3.3 percent of Chrysler from the VEBA trust fund, boosting its stake in the U.S. peer to 65.17 percent.

In July Fiat exercised its option for a first tranche of around 3.3 percent of Chrysler from the VEBA fund.

Fiat said it estimated the net amount to be paid for the purchase of this second tranche is $198 million.

The group said the Chancery Court of Delaware is expected to decide over the price for the transaction in the next months.

(Reporting by Antonella Ciancio)