The trend toward early retirement in America is continuing for both men and women, despite predictions by some experts that it would reverse itself, according to a Conference Board study released yesterday.

The study, based on the policies and practices of 363 companies, found that a large majority of the firms still encourage retirement before age 65.

More than three-fifths of the companies surveyed had pension provisions fostering early retirement, but only 3 percent provided incentives to work past 65.

"A reversal of the 25-year trend toward early retirement is not imminent," said Shirley Rhine, author of the study for the Conference Board, a business research organization.

Rhine found that only 14 percent of the companies had an average retirement age of 65 or over, compared with 42 percent in 1972. In half of the firms, the average retirement age was 62 or less, compared with 23 percent in 1972, she said.

"Efforts to discourage older workers from retiring before age 65 or to encourage them to postpone retirement beyond age 65 are exceedingly rare," Rhine said.

She said that the number of men 65 and over in the labor force has dropped from 48 percent in 1947 to 16 percent today. Rhine found that women as well as men are taking early retirement more frequently now than in the past.