WASHINGTON, May 22 (AP)  The first birth-control pill meant to put a stop to a woman’s monthly period indefinitely has won federal approval, the manufacturer said on Tuesday.

When taken daily, the pill, called Lybrel and made by Wyeth, can halt women’s menstrual periods indefinitely and prevent pregnancies.

It is the latest oral contraceptive approved by the Food and Drug Administration to depart from the 21-days-on, 7-days-off regimen that had been standard since birth-control pill sales began in the 1960s, and is the first made to put off periods altogether when taken without a break.

Wyeth, based in Madison, N.J., plans to start Lybrel sales in July. The company said it had not determined a price. The pill contains a low dose of two hormones already widely used in birth-control pills, ethinyl estradiol and levonorgestrel.