This story has been updated to reflect the most recent reporting.

Robert Frank became the third presidential finalist to drop out of Ohio University’s search this week, which leaves Duane Nellis, former president of Texas Tech University, as the sole candidate remaining in the search.

Frank, the former president of the University of New Mexico, emailed Board of Trustees Secretary David Moore to announce his withdrawal from contention Thursday. It is not immediately clear why he dropped out.

OU Executive Vice President and Provost Pam Benoit withdrew Wednesday, and Dean Bresciani, president of North Dakota State University, left the search Tuesday.

During his visit to OU, Frank outlined his initial plans if he were to be selected as OU president and discussed diversity and international students.

Frank decided last year not to seek a second term as the University of New Mexico’s president after he had a conflict with the university’s Board of Regents, according to a previous Post report. He left the university in early January.

Nellis, the final candidate in the search, serves as the university honors professor at Texas Tech. He served as Texas Tech’s president from June 2013 to January 2016, and before that, he spent four years as president of the University of Idaho.

Nellis was in the running for the presidency at the University of Wyoming but was not selected. According to The Texas Tribune, he expressed his frustration with the Texas Tech leadership, describing a “bit of tension” that arose from being in the same office building as the system’s chancellor, Robert Duncan.

During his forum Jan. 10, Nellis said diversity and transparency were two important aspects of serving as university president.

Nellis began his career as a geography professor and has spent almost 27 years as a higher education administrator.

He received his Ph.D. in geography from Oregon State University in 1980.

OU President Roderick McDavis will leave office Feb. 17, and David Descutner will take over as interim president Feb. 18.

The Board of Trustees is expected to announce the university’s next president Feb. 22 in Dublin.