Sept. 2 (Bloomberg) -- Wegelin & Co., Switzerlandâs oldest bank, is telling wealthy clients to sell their U.S. assets, or switch banks, because of concerns new rules will saddle investors with tax obligations in the worldâs biggest economy. U.S. proposals to extend reporting requirements for banks whose clients buy American stocks and bonds coupled with estate tax liabilities that may be inherited by the heirs of people who have such holdings prompted the advice from the St. Gallen, Switzerland-based bank, said Managing Partner Konrad Hummler. âWe came to the conclusion that itâs a threat to our clients,â Hummler, who is also president of the Swiss Private Bankers Association, said in an interview yesterday in Zurich. âItâs also a threat to us as a bank because as a custodian we are an executor to the estate. We find this aspect discomforting, so we recommend selling all American securities whatsoever.â Hummler said he plans to raise the subject today at a meeting of the Private Bankers Association, which counts Pictet & Cie., Lombard Odier & Cie. and Mirabaud & Cie. among its members. Swiss banks, which manage $2 trillion, or 27 percent, of the worldâs privately held offshore wealth, are struggling to protect bank secrecy after the government agreed to hand over the names of 4,450 UBS AG clients to U.S. tax authorities. Hummler said he wonât ask every member of the association to follow Wegelinâs lead. Wegelin, founded in 1741, manages more than 20 billion Swiss francs ($18.7 billion) in client assets. http://www.bloomberg.com/apps/news?pid=20601109&sid=aJstU9MVcYSg Ouch !