NEW YORK &#8212 Negotiations resumed Sunday between striking Broadway stagehands and theater producers struggling to find a solution to their thorny, seemingly intractable labor dispute as theaters faced a third week of dark stages and mounting box-office losses.

Resumption of the talks – after a week of no negotiating – had been announced the day before by Charlotte St. Martin, executive director of the League of American Theatres and Producers, and were confirmed by the stagehands union.

“We are glad they accepted our invitation to negotiate,” said Bruce Cohen, a spokesman for Local 1 of the International Alliance of Theatrical Stage Employees.

More than two dozen plays and musicals have been closed since Nov. 10, when the stagehands walked off the job.

The walkout was particularly felt during the last week, the lucrative Thanksgiving holiday, when most shows and theater-district restaurants do strong business. Not so this year, when only nine productions, including the newly reopened “Dr. Seuss’ How the Grinch Stole Christmas,” were playing, and 26 others were shut.

A settlement was believed to have been in the works last Sunday after a marathon weekend of negotiating, but the talks ended abruptly with producers walking out.

The complicated contract dispute has focused on how many stagehands are required to open a Broadway show and keep it running. That means moving scenery, lights, sound systems and props into the theater; installing the set and making sure it works; and keeping everything functioning well for the life of the production.

The producers want a flexible number; the union wants a set number and ample compensation for any concessions made.

The negotiations have been protracted. They began last summer.

The producers set up a $20 million strike emergency fund, taking a couple of cents out of each ticket sold over the past several years to pay for it. The money was to help struck shows struggling with costs.

The union, too, has its own fund – benefits of more than $4.1 million for its members, as well as another $1 million allotted for members of other unions affected by the walkout.

“Grinch” came back to life Friday after its reopening was ordered by state Supreme Court Justice Helen Freedman.

The judge said she believed the show’s production company would be irreparably harmed if the $6 million holiday musical wasn’t permitted to resume its limited run, which ends Jan. 6.