NEW YORK — Rabbi Samuel Cohen, a longtime Jewish communal leader, died Sept. 10 following a brief illness. He was 66.

Cohen, of Lawrence, N.Y., served in executive positions with many prominent Jewish organizations over four decades. But he is most closely associated with the Jewish National Fund, where he served as executive vice president for 20 years.

During his tenure, Cohen expanded the reputation and income of the fund-raising agency, best known for its tree-planting and land development projects in Israel.

He retired in 1997, the year after a controversial probe into the JNF's fiscal management cleared the organization of wrongdoing. Still, the probe led to a major reorganization of the charity.

Cohen continued to work as a consultant in connection with Jewish organizations until his death.

At funeral services, Rabbi Cohen was remembered as a devoted communal leader "who deeply believed in the people of Israel, the land of Israel and the Torah of Israel," said Malcolm Hoenlein, the executive vice chairman of the Conference of Presidents of Major American Jewish Organizations, who considered Cohen a mentor.

During the 1970s, Cohen served in an executive capacity at the American Jewish Congress and the American Zionist Federation, now the American Zionist Movement.

Earlier he worked for 11 years with B'nai B'rith and with the Long Island Zionist Youth Commission, a reflection of his lifelong interest in Zionism. Cohen was an ordained Orthodox rabbi and held a doctorate in education from Yeshiva University in New York.

A physically imposing figure remembered for his deep voice and impeccable grooming, Cohen also had an imposing leadership style.

His firm control of the Jewish National Fund was credited with raising the organization's profile outside the Jewish community and with increasing its annual campaign from $6 million in 1977 to about $30 million today.

At the same time, Cohen was associated by some with practices that led to a crisis of confidence in JNF's leadership and questions of fiscal accountability.

A 1996 investigation by a JNF-appointed panel found no malfeasance on the organization's part. However, it did note administrative and fiscal "inefficiencies" and revealed that only a small portion of money raised by the charity for land reclamation was reaching Israel.

As senior executive vice president, Cohen oversaw the ensuing reforms at the agency.

His successor, Russell Robinson, asserts that those reforms enhanced JNF's managerial and fiscal integrity.

"What I found when I came here — because of Dr. Cohen's charisma, his depth of Jewish knowledge and his love for Israel — was a group of lay leaders that had a commitment second to none," Robinson said.

Rabbi Bernard Lander, president and founder of Touro College, said he gave Cohen his first job as youth director at the Queens Jewish Center, where Lander was then president.

From that day, Lander said, Cohen never deviated from the path of service to the Jewish people, devoting himself "to Jewish life and the building of Jewish life here and in Israel."

A native of Asbury Park, N.J., Cohen came from a family of rabbis and communal leaders. His father was a long-time executive of the Agudas Harabonim, a rabbinic organization founded in 1902. His brother Jack is a rabbi in Melbourne, Australia, and his brother Chaim is a rabbi and dean of Touro College in Manhattan.

He is survived by his wife and three children.