NEW YORK — Twenty-six big U.S. companies paid their CEOs more last year than they paid the federal government in tax, according to a study released Thursday by a liberal-leaning think tank.

The study, by the Institute for Policy Studies, said the companies, including AT&T, Boeing and Citigroup, paid their CEOs an average of $20.4 million last year while paying little or no federal tax on ample profits, according to regulatory filings.

On average, the 26 companies generated net income of more than $1 billion in the U.S., the study said.