However, speculation is rife in the Italian market that the securitisation star will subsequently join a US firm, with Sidley Austin Brown & Wood foremost in the frame.
Chessa is understood to have had extensive talks with Sidley last year with a view to opening an office for the firm, which has a significant Italian structured finance practice. Clients are believed to include Morgan Stanley and Banca Intesa BCI.
The talks took place shortly before Clifford Chance's former Italian senior partner Vittorio Grimaldi evicted the magic circle firm from its Rome office. But Chessa then opted for Clifford Chance's offer of the joint managing partner role, along with Nick Wrigley.
Chessa follows former Clifford Chance partner Ian Bell to Standard & Poor's. Bell joined the rating agency as European counsel in 1999.
Chessa will be in high demand if he decides to return to private practice.
Sidley London managing partner Drew Scott would not comment on his firm's relationship with Chessa, but said Sidley's Italian strategy was under constant review.
“No strategic decision has been made on merger or opening an office in Italy,” commented Scott. “We're working with a number of firms. If something develops from that, then fine, but there are no formal relationships that we have entered into.”