Serge Etienne, a McLean contract negotiator, has to cancel business trips when it is necessary to take care of his ailing 88-year-old father. Helen Morris, an accountant for a Montgomery nuclear consulting organization, takes work home to make up for time lost tending to her 93-year-old mother. And Howard University secretary Joan Curry arrives late to work when her 71-year-old mother refuses to get up and get dressed in the morning.

"That is stressful," said Curry, who is one of a growing number of workers coping with such concerns as they carry on the timeless tradition of caring for aging relatives while earning a living.

But this burden has intensified and is becoming an important new productivity issue for corporate America because the elderly population is increasing rapidly and because the growth of two-career families has made it harder for families to devote time and attention to caring for the elderly -- either in their homes or over long distances.

"The emotional and financial toll of caring for an elderly relative often has negative effects on an employe's work," said Dana E. Friedman, a work-family research specialist at The Conference Board, a national business information service that organized a recent seminar on the issue. Workers' care of the elderly is a bottom-line business concern that companies are beginning to confront, she said.

Elder care, as the issue has been called, can cost employers money as a result of lost work because of tardiness, absenteeism, lack of concentration from worrying about what is happening at home, and extensive use of the office telephone for personal calls involving the relative, according to gerontologist Michael A. Creedon, director of elder care research at the University of Bridgeport in Connecticut.

One in four workers provides care for an aging relative today, Creedon said, and that number will increase as the population ages.

Creedon estimates that 6.6 million people over the age of 65 need some form of assistance from others. The number will climb rapidly during the remainder of this century and reach 9 million by 2000 and 19 million by 2040, he estimates.

A small number of companies have begun to offer support services for their workers who have elder care responsibilities.

Southwestern Bell has published a manual listing community services that can help workers locate assistance for elderly parents. The Travelers insurance group offers counseling aimed at workers stressed out from parental care. Stride Rite Corp. is considering the addition of adult day care to the child care center at its headquarters in Cambridge, Mass.

For the so-called "sandwich generation" of middle-aged workers -- sandwiched between their children and their parents -- elder care may start as soon as child care stops, said gerontologist Elaine Brody, one of the leading authorities on the subject. "The empty nests" created when children grow up and move away from home "are being filled with parents," she said. Often, workers end up with dual dependents -- their small children and their older parents.

Generally, a worker who is caring for a parent spends an average of 12 hours per week in care giving and may spend more than 35 hours per week, according to a 1985 study by The Travelers.

Creedon said that stress produced from the double burden of work and elder care can surface on the job in several ways. Studies indicate, for instance, that workers providing such care are more likely to be under a physician's care themselves than workers without elder care responsibilities and are more likely to experience depression, headaches and weight gains or losses.

This can translate into higher health costs for the worker and his company, Creedon said.

Employer response to elder care problems is still "spotty," Creedon said. Many employers do not consider it a problem, he said, and the companies that now regard it as a bottom-line issue have responded with limited programs, such as providing workers with information about elderly services in their community.

That may not help much, Creedon said, if those community services are inadequate or nonexistent.

But elder care -- which The Conference Board describes as the emerging employe benefit of the 1990s -- is gaining some momentum, Creedon said, as companies look for ways to help workers with counseling and flexible work hours as well as information.

The American Association of Retired Persons, in anticipation of corporate interest, has developed a kit that tells companies how to organize elder care services for their workers, including information fairs and educational seminars.

About 1,200 companies across the nation have asked for the kit, according to AARP program specialist Angela Heath, "and that's without any publicity."

In the Washington area, some firms such as Potomac Electric Power Co. give workers unpaid leave to tend to family problems involving elders as well as children. Others have begun to offer workers access to dependent care benefit plans, which offer a tax break on costs associated with the care of dependent parents and children.

Elder care counseling is being added to the program of services offered by the Institute for Human Resources, a Washington firm that has a contract to provide counseling to employes of Marriott Corp., Eastern Airlines, American Security Bank, Roy Rogers restaurants and a number of other major firms.

"A few years ago, elder care responsibilities of employes were considered by industry to be a personal and private matter, not the concern of the work place. That is changing," said Barbara Kane, whose private agency, Aging Network Services of Bethesda, provides counseling to employes.

For Serge Etienne, 56, elder care has become an increasingly difficult burden to manage in recent weeks as the condition of his father, Serge, 88, who has Parkinson's disease, has worsened.

"He was in pretty good shape when he moved in with me three years ago," the younger Etienne said, "and I didn't want to relegate him to a nursing home at that time."

Instead, Etienne, who is divorced, has been taking his father to the Lewinsville Daycare Center for the Elderly in McLean while Etienne works at the Mitre Corp.

His father has been hospitalized several times recently, and "he gets dizzy and falls, and I have to watch out for him. He can't get any of his own meals, except for coffee. He needs a little help getting in and out of the shower," Etienne said.

To care for his father, Etienne has canceled several recent business trips. This past week, after finding a round-the-clock attendant to stay at home with his father, Etienne went to San Diego on business. "I decided an hour and a half before flight time that it would be all right for me to leave," he said.

But Etienne went home before his business was concluded, to care for his father. "At some point, other arrangements will have to be made," Etienne said.

Helen Morris has been taking care of her mother, Emma Docekal, 93, for about 18 years. Eight years ago, when her mother began to wander away from Morris' home in Potomac, Morris realized that she could no longer leave her mother unattended. This past year the deterioration has accelerated, Morris said.

"She still walks, but she is very shaky," Morris said. "She can hardly hear at all, and her eyesight is very poor. And although she has spoken English ever since she came here as a girl, 17 years old, from Czechoslovakia, she has reverted to Czech."

Because Morris speaks Czech, she can communicate with Docekal. And at the Fellowship House in Bethesda where Docekal spends the day, staff members communicate with her using a combination of sign language and pantomime.

But when Docekal had three hematomas within a six-week period and had to be hospitalized for treatment, Morris "would run in and out from work to Suburban Hospital to see her, feed her, communicate with her what was going on because she didn't understand."

To get her work done, Morris took it home. "This past winter, when she had a bronchial infection, I went to the office in the evening to pick up the work and then did it at home," she said.

The stress from all this is "something you learn to handle," Morris said. "Sometimes she doesn't know me. She thinks of me as her sister now. It takes time to accept these things. It is so mentally disturbing because you are basically losing your parent right there."

For Joan Curry, the hardest part of caring for her mother and holding down a job is the morning rush to get dressed.

"If she isn't ready when the bus from Iona House day care center comes to pick her up, it may cause me to be late for work," Curry said. Some mornings she has to persuade her mother, Ida Curry, who has Alzheimer's disease, to get dressed and then watch to make sure her mother does not misplace anything, such as her eyeglasses, that might cause a delay.

Two years ago when Ida Curry began slipping, Joan Curry was working as a clerk in Washington and trying to finish her law degree at Antioch School of Law. But Curry put aside her plans to pursue a legal career and concentrated on resettling her mother, whom she described as having been an independent and sophisticated New York psychologist.

Eventually Curry lost her clerical job. "My supervisor was sympathetic, but she said that I was spending too much time away from my job," Curry said.

At night, Curry could not sleep, and during the day she had chest pains from the tension. "My mother would call me at work to say she was going to leave our apartment for various reasons, and I would have to take time off or take an extended lunch break to go and deal with my mother," Curry said.

Curry, who now has a secretarial job, says her life has settled down in recent months. Her mother likes Iona House and seems better adjusted, and Curry has a homemaker to stay with her mother three afternoons a week. "That allows me some time to be with friends, or if I have to shop I don't have to break my neck to get home and feed her and take care of any needs she has," Curry said.

Now Curry, having overcome one hurdle, is ready for another.

"We are relocating to Hawaii," Curry said. She wants to resume her legal career plans. "My mother will travel with me," Curry said. "I have been in touch with the office on aging there, and they will help find the services we need. We leave in the fall."