WASHINGTON — A new effort to discourage companies from setting up headquarters offshore to avoid U.S. income taxes could affect some insurers more than others.

President Obama and Treasury Secretary Timothy Geithner today unveiled a proposal that they say will curb use of foreign tax havens, by discouraging U.S. multinationals from keeping foreign earnings offshore indefinitely. A separate proposal would discourage multinationals from moving U.S. jobs overseas.

The section of the tax proposal that seems most likely to affect insurers concerns the rules for deferring payments of taxes on earnings from overseas investments.

“Currently,” officials write in a description of the tax proposal, “businesses that invest overseas can take immediate deductions on their U.S. tax returns for expenses supporting their overseas investments but nevertheless ‘defer’ paying U.S. taxes on the profits they make from those investments. As a result, U.S. taxpayer dollars are used to provide a significant tax advantage to companies [that] invest overseas relative to those [that] invest and create jobs at home. The Obama administration would reform the rules surrounding deferral so that – with the exception of research and experimentation expenses – companies cannot receive deductions on their U.S. tax returns supporting their offshore investments until they pay taxes on their offshore profits.”

Joe Sieverling, a senior vice president at the Reinsurance Association of America, Washington, and George Burke, a spokesman for the American Council of Life Insurers, Washington, say it looks as if the effects of the proposal could vary widely from company to company.

Some insurers with large overseas operations may have to wait until they repatriate offshore profits to the United States before they can deduct the costs associated with financing foreign operations, Sieverling and Burke say.

But the administration made it clear that more international proposals will be coming out later this month, and it is too early to tell whether any of those will be specific to the insurance industry, Sieverling says.

Today, he notes, the administration made no mention of a bill that Rep. Richard Neal, D-Mass., is expected to introduce later this month.

Neal, chairman of the Select Revenue Measures Subcommittee of the House Ways and Means Committee, wants to rein in a type of related-party reinsurance transaction. Domestic insurers say offshore insurers with U.S. operations use the related-party transactions to cut their tax bills.

The foreign parents involved have their U.S. units cede premiums to the parents’ offshore reinsurance units.

Analysts at Washington Analysis, Washington, say the administration’s proposal was far less comprehensive than expected and is unlikely to be implemented for tax years before 2011.

Earlier, administration officials estimated eliminating deferral of taxes on foreign earnings could raise $220 billion in additional tax revenue over 10 years.

The proposal introduced today would raise just $60.1 billion over 10 years, the analysts write.

“In other words, it is much less severe than what was possible or perhaps feared,” the analysts write. “[The] retreat likely reflects the significant corporate backlash against the initial proposal.”