Complex sentence: It was designed by architect Luca Beltrami in the early 20th century for Banca Commerciale Italiana (BCI, a prominent Italian bank), and it is still in use as a seat of the company (now merged into Banca Intesa).
Split into simpler sentences: It was designed by architect Luca Beltrami in the early 20th century. The building was commissioned by Banca Commerciale Italiana (BCI, a prominent Italian bank), and it is still in use as a seat of the company (now merged into Banca Intesa).