Negotiations between the Hollywood writers’ union and the major entertainment companies resumed on Wednesday after a month, with top executives joining the talks for the first time.

The day ended with the two sides issuing a statement saying they would meet again on Thursday, and the top executives were expected to return. One person familiar with the discussions said the results were encouraging.

In attendance were Ted Sarandos, a co-chairman of Netflix; David Zaslav, the chief executive of Warner Bros. Discovery; Donna Langley, the chief content officer of Universal Pictures; and Robert A. Iger, Disney’s chief executive, according to three people familiar with the meeting, who spoke on the condition of anonymity because of the diplomatic nature of the negotiations.

Last month, the Alliance of Motion Picture and Television Producers, which bargains on behalf of entertainment companies, sweetened its offer for a new three-year contract, publicly disclosing the details. The choice to make the offer public only rankled the Writers Guild of America, which represents more than 11,000 television and film writers, and was one of the reasons for the latest impasse. Top executives like Mr. Zaslav and Mr. Iger met with union officials last month, but not in a formal bargaining session.

The writers initially refused to respond to the studios’ latest offer but then reached out to the alliance last week to request a new meeting.

At 142 days, the strike is on its way to becoming the longest writers’ walkout ever. (The longest was 153 days in 1988.) The union is arguing that the streaming era has worsened its members’ pay and working conditions.

Studios have said they are offering the highest wage increase to writers in more than three decades, while also including protections against artificial intelligence.

The damage that the writers’ strike — along with one by Hollywood actors, which began on July 14 — has done to the industry and its surrounding businesses has been significant.

Gov. Gavin Newsom said in an interview on CNN last week that he believed the dual strikes had already cost California’s economy north of $5 billion.

Brooks Barnes and John Koblin contributed reporting.