NEW YORK—In a unanimous vote yesterday, the Solomon R. Guggenheim Foundation's board of trustees appointed Richard Armstrong the new director of the foundation.

Armstrong, 59, has led the Carnegie Museum of Art in Pittsburgh since 1996, where he oversaw the renovation of many of the museum's galleries, the expansion of the museum's holdings, particularly in contemporary art, and the increase of the museum's endowment. He announced his retirement from the Carnegie in June.

In his new role, Armstrong will preside over the foundation, the foundation's flagship museum in New York, and the four other Guggenheim institutions: the Peggy Guggenheim Collection in Venice, the Guggenheim Museum in Bilbao, the Deutsche Guggenheim in Berlin, and the Guggenheim Abu Dhabi Museum, scheduled to open in early 2013.

"Richard Armstrong has the wisdom and demeanor — as well as the knowledge, statue, and status — we sought in a new leader for the foundation," said William L. Mack, chairman of the board of trustees. "But there's more: He clearly demonstrated a passionate kinship with the Guggenheim's singular exhibition program, its collections, and with its global mission of promoting the understanding and appreciation of modern and contemporary art and architecture."

Armstrong begins at the Guggenheim on November 4.