WASHINGTON -- A new Internal Revenue Service enforcement unit targeting the very wealthy will help the IRS decode partnerships, offshore trusts and other complex techniques used to hide income, IRS Commissioner Doug Shulman said Monday.

Dubbed the Global High Wealth Industry group, the unit will launch "a small number" of audits of individuals with assets or income in the tens of millions, Mr. Shulman told an accountants' trade group. An IRS official said the group would begin work on these initial audits in the next month.

The high-wealth group, housed in the IRS's large and medium-sized business division, marks a sharpening of IRS approach to auditing the very wealthy. Its creation is a response to the complex web of entities and transactions many high net-worth individuals use to manage their financial affairs.

"You cannot assess compliance among the nation's wealthiest individuals by looking only at their 1040s," said Mr. Shulman. "Our goal is to better understand the entire economic picture of the enterprise controlled by the wealthy individual and to assess the tax compliance of that overall enterprise."

IRS has seeded the group with experts in partnership and corporate taxation and cross-border transactions.

The re-organization is another plank in a multi-front IRS effort to crack down on tax evasion by wealthy Americans. The agency is now sifting through the results of a partial amnesty program that netted 7,500 disclosures by Americans that held offshore accounts.

The IRS and the Obama administration have also asked Congress for expanded third-party reporting requirements and legal authority to catch untaxed money flowing offshore.