UBS’s (UBSG.VX) chairman said a default by Greece is seen by the International Monetary Fund as “systemically controllable” and he believed it would have a negligible impact on the Swiss bank itself, according to a newspaper interview published on Saturday. Euro zone finance ministers told Greece on Friday that its leftist government would get no more aid until it agreed a complete economic reform plan. In an interview with Neue Zuercher Zeitung, the chairman of Zurich-based UBS, Axel Weber, addressed the alternative if euro zone and Greek officials fail to reach an agreement.