The new union, which was approved by a vote of 57-20, will represent about 140 employees at the museum, including full time engineers and maintenance mechanics who operate the Guggenheim’s heating and air conditioning systems, as well as full-time and temporary employees with titles like art handler, cabinetmaker and fabricator, who install and take down exhibits.

Guggenheim officials had hoped to dissuade workers from joining the union.

Local 30 officials said Richard Armstrong, the museum’s director, sent workers an email earlier this week in which he said he believed a union would inject divisiveness “on a daily basis” into the institution.

The formation of a Guggenheim union comes as increasing attention is being focused on the pay scales of workers at prestigious cultural institutions. Some staff members at the Museum of Modern Art walked out last summer during labor negotiations that ended with a new contract that included wage increases.