UBS on Wednesday began selling Additional Tier 1 (AT1) bonds — which were at the heart of controversy during its emergency rescue of Credit Suisse — for the first time since completing the takeover. The Swiss banking giant is marketing two tranches of U.S. dollar AT1 bonds, a noncall five-year offering around a 10% yield and a noncall 10-year offering around 10.125%, according to LSEG news service IFR. Noncall bonds are bonds that only pay out at maturity. UBS confirmed to CNBC that it is offering Additional Tier 1 securities, but did not comment on the details of the contracts and said it will provide additional information when the offering is complete. The wipeout of $17 billion of Credit Suisse AT1 bonds, as part of the rescue deal brokered by Swiss authorities in March, caused uproar