After four days of marathon negotiations, the Writers Guild of America could reach a deal with major film and television studios as early as Sunday, sources told CNN.

A tentative agreement would still need to be ratified by members of the WGA, which represents more than 11,000 writers. But if passed, a deal would mark the end of a nearly five-month-long strike, the second-longest in the union's history.

The actors' union, SAG-AFTRA, has also been on strike since mid-July. Both unions have similar sets of demands, including better wages, residuals payments from streaming services for their work, and job protections against the use of artificial intelligence.

If the WGA reaches a deal with the Alliance of Motion Picture and Television Producers, the trade association representing major Hollywood studios, SAG-AFTRA could feel increased pressure to settle for a deal along the same lines.

This is a developing story and will be updated.