UNITED NATIONS-Cracking a glass ceiling for women in the Arab world’s most conservative nation, the U.N. chief on Wednesday appointed Thoraya Ahmed Obaid of Saudi Arabia to head the U.N. agency that promotes family planning, sexual health and women’s equality.

Obaid, an American-educated expert on women’s issues who has worked for the United Nations for 25 years, will replace Dr. Nafis Sadik as executive director of the U.N. Population Fund on Jan. 1.

Introducing Obaid at a news conference, Secretary-General Kofi Annan called her an outstanding U.N. professional whose work in social affairs has made her “sensitive to the cultural issues” involved in promoting often controversial population measures.

“Her record in working for reproductive rights for women, in promoting choice and improving women’s health, is second to none,” Annan said. “She is conscious of the vital importance of promoting the rights of women and adolescent girls in order to safeguard their reproductive health.”