Joseph Stein, an American architect who designed some of India's most important modern buildings, died on Oct. 6 in Raleigh, N.C. He was 89.

In the nearly half-century he spent in India, Mr. Stein won acclaim for marrying his structures to the natural landscape. He favored buildings that merged into the trees, lawns and ponds surrounding them, and later in life he became increasingly concerned with protecting the environment, particularly the Himalayas.

In ''Building in the Garden,'' a study of his work, Stephen White, dean of the School of Architecture at Roger Williams University in Rhode Island wrote that Mr. Stein ''developed a vocabulary of carefully crafted building forms responsive to the subtleties of place and culture,'' and combined it with ''a sense of responsibility for the total, both designed and natural.''

Mr. Stein's best-known Indian creations were probably a collection of buildings on Lodi Estate in New Delhi, including headquarters of the Ford Foundation, Unicef and the World Wide Fund for Nature, a conference center called the India International Center, and the India Habitat Center for housing and environmental studies.

These buildings are typically low, campuslike structures protected from the sun by vertical slats or trellised walls, surrounded by trees and water and with flowers cascading down their walls in what Mr. Stein called ''vertical gardens.''

Other notable buildings include Triveni Kala Sangam in New Dehli, an Indian arts center with an open-air theater; several factories with roofs inspired by the domes used in traditional Indian architecture; and the Kashmir Conference Center, built against a snowy mountain backdrop near Srinagar.

Mr. Stein was also a major contributor to three of the four new industrial towns built by India's first prime minister, Jawaharlal Nehru, in his drive to modernize the country.

Joseph Allen Stein was born on April 10, 1912, in Omaha. After studies at the University of Illinois and work in New York and Los Angeles, he established a practice in San Francisco.

In 1952 he moved to India, and became head of the department of architecture at the Bengal Engineering College in Calcutta.

Several other foreign architects arrived in India about the same time, including the great French architect Le Corbusier, who was designing the new Punjab capital city at Chandigarh, as well as the Americans Louis Kahn and Charles Eames, who were working on projects at Ahmedabad.

But unlike them, Mr. Stein stayed on. He practiced in New Delhi from 1955 until his retirement in 1995, when he again chose to remain.