The battle for unisex insurance rates is going nowhere at the federal level. So the troops have switched to guerrilla tactics: They're trying to pick off the states one at a time, until the opposition collapses.

"We hope that if enough states require unisex pricing, each with its own separate regulations, it will screw up things so much for the insurance industry that they will sponsor federal legislation, just to make things uniform," one source said.

Rob Bier of the American Council of Life Insurance says that if unisex pricing prevails in a populous state like Massachusetts, California or New York, it might force the companies to adopt at least part of that pricing, on some products, nationwide.

Montana has become the first state in the union to require equal insurance prices for men and women across the board. That law takes effect on Oct. 1. Bills in the Massachusetts Legislature would outlaw price discrimination in annuities, health and disability insurance (the life-insurance industry has been lobbying strenuously to keep life insurance out of the package).

Four states -- Hawaii, North Carolina, Massachusetts and Michigan -- already require unisex pricing for auto insurance. Pennsylvania's Supreme Court just upheld a rule requiring unisex auto pricing there, too -- the change to take effect Oct. 1.

Three bills have been introduced in the Pennsylvania Legislature to overturn the court decision and legalize sex-based pricing on auto, health and life insurance. But similar resistance in Montana failed.

Significantly, the Pennsylvania court found that sex-based pricing for auto insurance violated that state's equal-rights amendment -- a principle that could be expanded to include life, health, annuity and disability policies in that state.

It also suggests that the equal-rights amendments passed by 15 other states might be the lever the activists need to force wide adoption of unisex pricing. Equal-rights laws exist in Alaska, Colorado, Connecticut, Hawaii, Illinois, Maryland, Massachusetts, Montana, New Hampshire, New Mexico, Pennsylvania, Texas, Utah, Virginia, Washington and Wyoming.

A lawsuit in the District of Columbia, brought by the National Organization for Women (NOW), claims that charging women a higher rate than men for their health insurance violates the District's anti-discrimination law covering public accommodations. If won, that argument could be carried to 26 states with similar laws.

NOW's Pat Butler told my associate, Virginia Wilson, that there's activity in New York and Washington, among other states.

Unisex pricing is an issue only for the individual insurance policies that you buy yourself. Discrimination in group plans (affecting more than 15 employes) was barred by Supreme Court decisions in 1978 and 1983, which found them in violation of civil-rights laws. For all the beating of breasts and grinding of teeth, insurers survived the group move to equality, and will survive it in individual policies, too.

Right now, women have an advantage in some insurance products while men have an advantage in others. But the winners and losers aren't as easy to pinpoint as it sounds.

For example, women are said to benefit from the current system of separate-sex pricing for life insurance because they pay less for their coverage than men. (The size of their price break varies, depending on the company.) Men, who average shorter life spans than women, have to pay more.

But men's higher rates are a distinct disadvantage to a very large and important class of women -- namely, their wives. The higher male rate means that the family has less to spend on other things. It also means that, dollar-for-dollar, a surviving wife gets less from her husband's life-insurance policy than she would if men and women paid the same rates.

Unisex pricing would raise life-insurance rates for insured women (although perhaps not by very much). But it also would lower rates for men -- thereby making it possible for husbands to buy more insurance per dollar to protect their wives.

Single women get a break on their auto insurance. But if they're married, they're presently charged the male rate, so they'd be helped by unisex pricing that lowers male rates.

Women are charged vastly more for annuities, health insurance and many disability policies -- so in these areas, unisex pricing would lower their costs.

Insurance-industry lobbyists have been threatening women with much higher life- and auto-insurance rates, if unisex pricing becomes law. But in the four states now requiring unisex pricing for auto coverage, some women paid more and some didn't. When new rates are filed in October, in Montana, we'll know more about where the costs and savings are going to lie.