WASHINGTON (AP) — Apple Inc. employs a group of affiliate companies located outside the United States to avoid paying billions of dollars in U.S. income taxes, a Senate investigation has found.

The world's most valuable company is holding overseas some $102 billion of its $145 billion in cash, and an Irish subsidiary that earned $22 billion in 2011 paid only $10 million in taxes, according to the report issued Monday by the Senate Permanent Subcommittee on Investigations.

The strategies Apple uses are legal, and many other multinational corporations use similar tax techniques to avoid paying U.S. income taxes on profits they reap overseas. But Apple uses a unique twist, the report found. The company's tactics raise questions about loopholes in the U.S. tax code, lawmakers say.