WASHINGTON/SAN FRANCISCO (Reuters) – Using an unusual global tax structure, Apple Inc (AAPL.O: Quote, Profile, Research, Stock Buzz) has kept billions of dollars in profits in Irish subsidiaries to pay little or no taxes to any government, a Senate report on the company’s offshore tax structure said on Monday.

In a 40-page memorandum released a day before Apple CEO Tim Cook is scheduled to testify before Congress, the Senate’s Permanent Subcommittee on Investigations identified three subsidiaries that have no “tax residency” in Ireland, where they are incorporated, or in the United States, where company executives manage those companies.

SAN FRANCISCO (Reuters) – Apple Inc will argue for a comprehensive corporate tax reform that will levy a “reasonable tax” on foreign earnings and is not dependent on a company’s revenue when it goes before a Senate panel on Tuesday to explain its offshore tax practices.

In prepared testimony released by the company and submitted ahead of Apple Chief Executive Tim Cook’s hearing on Tuesday before the Senate Permanent Subcommittee on Investigations, Apple denied it employed “tax gimmicks” like using Cayman Islands bank accounts or shifting intellectual property abroad.

SAN FRANCISCO (Reuters) – Dell Inc, the subject of a takeover battle between activist investor Carl Icahn and the company’s billionaire founder, reported a 79 percent slide in profit as personal computer sales continued to shrink.

The disappointing results lend weight to Michael Dell’s effort. The man who started Dell from a college dorm room wants to take the world’s No.3 PC maker private for $24.4 billion, arguing its transformation into a provider of enterprise computing services is best done away from market scrutiny.