Wealthy Americans Under Scrutiny in UBS Case

By LYNNLEY BROWNING

One afternoon in April, six dozen wealthy Americans were entertained at a luncheon party in Midtown Manhattan, along with a special guest from Paris: Henri Loyrette, the director of the Louvre.

The host of the exclusive gathering was the Swiss bank UBS, whose elite private bankers built a lucrative business in recent years by discreetly tending the fortunes of American millionaires and billionaires. As the wine flowed and Mr. Loyrette spoke of the glories of France, UBS bankers courted their affluent guests.

But now, as the federal authorities intensify an investigation into offshore bank accounts, the secrets of this rarefied world are being dragged into the open — and UBS’s privileged clients are running scared.