SACRAMENTO – Finance officials from 10 states, including Maine, on Thursday asked Standard & Poor’s to remove 10 offshore companies from the S&P 500 Index.

The request is the latest in a series of attempts to pressure the companies to reregister in the United States.

National labor officials joined the state officials in arguing the companies aren’t paying their fair share of taxes because they’re based in places such as Bermuda or the Cayman Islands.

Standard & Poor’s immediately rejected the request, saying its index is designed to reflect the broad U.S. stock market. The committee that makes the selections takes no position on tax policy or on how U.S. companies nominally headquartered offshore should be treated, the company said in a statement.

That reasoning “ignores the fact that these companies, by their own choosing, are not U.S. companies – they’ve renounced their citizenship,” said California Treasurer Phil Angelides. “It’s a disservice to investors. … They’re as American as Bermuda.”

S&P said it relies on several factors in determining whether a company should qualify as U.S.-based regardless of its corporate headquarters, including the location of the company’s operations, its corporate structure, accounting standards, the stock exchanges on which its shares are listed and its office locations.