Fiat SpA says it has exercised an option to purchase a 28.63% stake in Ferrari SpA for about €892 million ($1.13 billion).

The purchase of shares held by a group of banks led by Mediobanca brings Fiat’s holding in Ferrari to 85%.

Mubadala Development Co., which controls a 5% stake in Ferrari, is expected to hang on to its shares, Fiat says.