SAN FRANCISCO (AP) ― John Steinbeck’s heirs say a literary agency is wrongly cutting them out of negotiations over movie deals for the late Nobel Prize-winning author’s books.

Steinbeck’s surviving son, Thomas Steinbeck, and the wife of another son, Nancy Steinbeck, filed a petition Oct. 10 with the California Labor Commission claiming the RSWG Literary Agency and agent Geoffrey Sanford were negotiating Hollywood deals without consulting them.

They also allege that the agency isn’t licensed in California to negotiate deals and that none of its agents are lawyers with active licenses. The petition alleges that only a licensed agency or an active lawyer can license Steinbeck’s works to others.

The petition says that Thomas Steinbeck first became aware through news media that that his father’s books “East of Eden” and “The Grapes of Wrath” were being considered for new movie treatment. The petition says that Thomas Steinbeck “either owns or controls” 66.6 percent of domestic rights to his father’s works.

It’s the latest chapter in a 14-year legal tussle over control of Steinbeck’s works.

The agency’s lawyer told the Monterey Herald that Thomas Steinbeck and Nancy Steinbeck gave up control over Steinbeck’s works as part of a 1983 legal settlement. The lawyer also said the agency is licensed to practice in California. The lawyer further said that the family of Steinbeck’s third wife controls the works.

The fight began after the author’s death in 1968. Steinbeck left control of his work to his third wife Elaine Steinbeck even though copyright law at time stated rights went to his children, his two sons from a previous marriage.

The parties agreed to a settlement in 1983 that left control with Elaine Steinbeck and gave the children a cut of any proceeds. The fight flared anew when Elaine died in 2003 and left control of the works to her children from a previous marriage. Two federal courts upheld those terms.