(Bloomberg) Americans renouncing U.S. citizenship surged sixfold in the second quarter from a year earlier as the government prepares to introduce tougher asset-disclosure rules.

Expatriates giving up their nationality at U.S. embassies climbed to 1,131 in the three months through June from 189 in the year-earlier period, according to Federal Register figures published today. That brought the first-half total to 1,810 compared with 235 for the whole of 2008.

The U.S., the only nation in the Organization for Economic Cooperation and Development that taxes citizens wherever they reside, is searching for tax cheats in offshore centers, including Switzerland, as the government tries to curb thebudget deficit. Shunned by Swiss and German banks and facing tougher asset-disclosure rules under the Foreign Account Tax Compliance Act, more of the estimated 6 million Americans living overseas are weighing the cost of holding a U.S. passport.

“With the looming deadline for Fatca, more and more U.S. citizens are becoming aware that they have U.S. tax reporting obligations,” said Matthew Ledvina, a U.S. tax lawyer at Anaford AG in Zurich. “Once aware, they decide to renounce their U.S. citizenship.”

Fatca requires foreign financial institutions to report to the Internal Revenue Service information about financial accounts held by U.S. taxpayers, or held by foreign entities in which U.S. taxpayers hold a substantial ownership interest. It was estimated to generate $8.7 billion over 10 years, according to the congressional Joint Committee on Taxation.