Two-thirds of those acting as caregivers for elderly relatives lose out at work by forgoing promotions, pay raises and training opportunities, a new study says.

The study, by the National Center for Women and Aging at Brandeis University and the National Alliance for Caregivers, focused on 55 people who spent more than eight hours per week providing unpaid care.

Among the 30 subjects who could provide detailed financial information, the average loss over a lifetime was $659,139 in wages, pension and Social Security benefits, according to results to be released today.

Although the study involved few participants, it is the first to detail financial losses for caregivers, three-quarters of whom are women, said Phyllis Mutschler, executive director of the National Center for Women and Aging.

Previous studies have largely focused on what it would cost to replace a caregiver, she said.

"Once a person has fallen off an earning trajectory, they don't tend to regain ground," Mutschler said. "From the time of retirement to when they die, caregivers will have fewer benefits."

The project's participants came from a 1997 study of 1,509 people that found one in four families had at least one member who had provided care for an elderly relative or friend in the past year.

The 55 subjects were all over age 45 and had provided either physical or administrative care for a parent, spouse, sibling or friend for an average of eight years.

The respondents reported making frequent work sacrifices, both large and small.

Sixty-nine percent reported arriving late or leaving the workplace earlier than normal; 67 percent reported taking time off during the day to attend to an elderly dependent.

Sixty-four percent of respondents said they used sick days or vacation time for caregiving duties while 22 percent said they took a leave of absence, and 20 percent reduced their career from full to part time. Sixteen percent quit their jobs, and 13 percent retired early to devote more time to an elderly person.

Twenty-nine percent said they had passed up a promotion or training assignment and 25 percent said they had refused a transfer because of their caregiver duties.