DALLAS — Looking for a job was an exercise in frustration for Mike O’Bryan, and nothing was more aggravating than the interview.

His 25 years in information technology turned out to be more a liability than an asset. Employers looked at the 60-year-old applicant and asked him whether he might be “overqualified.”

“I guess my age scared them,” he said. “They must have thought that if they hired me, I’d retire soon.”

After a dozen disappointing interviews, O’Bryan decided to become a self-employed financial planner. With retirement nowhere on his horizon, he helps his clients plan for their golden years.

“I’m now my own boss. It’s OK,” said O’Bryan, who lives in Grapevine, Texas.

The weak economy is putting a squeeze on workers in their 50s and 60s. Having spent their career with only one or two employers, many are looking for work for the first time in years. Some have been laid off. Others have taken buyouts but can’t afford to retire. Still others are coming out of retirement because their nest eggs have shrunk.

Workers 55 and older take an average of 21 weeks to find a job, about 5 weeks longer than younger job seekers, according to the AARP Public Policy Institute.

The interview can be especially intimidating to workers over 50. So career counselors who coach them try to prepare them for it, going over how to dress and act and even how to answer the tougher questions they’re likely to be asked.

“Your resume may get you in the door, but how you handle the interview determines whether you get the job offer,” said career consultant Jill Pfaff Waterbury of Coppell, Texas.

Waterbury, who’s co-author of the Boomers’ Job Search Guide and teaches a community college course for older job seekers, said no one can survive an interview without conveying a professional image and confident attitude.

First and foremost, brush off that chip on your shoulder. “If you don’t believe that your age and experience would be assets to potential employers, why should they believe it?” said Renae Perry, director of the Senior Source’s employment program.

Work on your image. Even applicants with a can-do attitude can defeat themselves with a slothful appearance, Waterbury said. “No one expects you to look like you’re 20, but you should look neat, trim and up-to-date,” she said.

Don’t be rattled if your interviewers are under 30. “Show them respect,” Perry said. “Keep your conversation on a professional level. You’re there to convince them you can help them. But don’t overdo it and make them think you’re after their job.”