"Although both candidates presented good qualifications, the board was unable to make an offer of employment," Werner said.
The library board will begin a new search for an executive director, he said.
"Steps are being taken to examine the recruitment process with a focus on attracting top quality applicants who will be a good match for the specific needs of our organization," Werner said in a prepared statement.
The process of finding the right person might take some time, he said. "But the time spent will be a good investment."
Werner added that the board has confidence the library staff will continue to provide quality service to the public while the search continues.
In the meantime, Linda Hamilton will remain interim director. She is credited with calming the waters after the stormy departure of former Executive Director Beth Elder in October 2011.
Although staff morale has been buoyed under Hamilton there remains some anxiety about the selection of a new executive director, said Brooke Young, a 15-year library employee and vice chairman of the employees group.
"This doesn't ease any of those worries," she said. "But I support the board's decision. I'm happy they are taking such great care" to find a new director.