By Jessica Toonkel

(Reuters) - Attorneys for Sumner Redstone and his daughter asked a court to reject Viacom Inc <VIAB.O> Chief Executive Philippe Dauman's request to move up the trial over Dauman's removal from the media mogul's trust, according to court filings on Friday.

Sumner Redstone's lawyers said the claims by Dauman and Viacom board member George Abrams were motivated by "self interest." Attorneys for daughter Shari Redstone said they would file by June 16 a motion to dismiss Dauman's case.

Last month, Redstone removed Dauman and Abrams from the trust that would determine the future of CBS Corp <CBS.N> and Viacom after controlling shareholder Redstone, 93, dies or is declared mentally incapacitated.

Dauman fired back with a lawsuit questioning Redstone's mental competence. He argued that replacing him and Abrams on the trust and the National Amusements Inc board would lead to an unlawful corporate takeover by Shari Redstone.

Les Fagen, an attorney for Dauman and Abrams, said on Friday in a statement: "There are many undisclosed facts that will emerge concerning the conduct of Shari and her representatives."

Dauman has asked a Massachusetts court to hold a trial by the end of September. A hearing on that request is scheduled for Tuesday.

In a legal motion on Friday, Sumner Redstone's attorneys argued that Dauman and Abrams were enacting "an acutely self-interested legal strategy that they began plotting months earlier to secure their tenuous positions with Viacom."

They also said a majority of the other trustees had ratified Abrams' and Dauman's removal. "Plaintiffs are therefore off the trust, and off the board, even if they could somehow prove the allegations in their complaint," the motion said.

Shari Redstone has said her father made his own decisions. Her attorneys, in a separate filing to the Massachusetts court on Friday, said Dauman and Abrams apparently had no concerns as to Sumner's competence until he took them off the trust.

Attorneys for the Redstones also asked the court to let the case be handled in California, where Sumner Redstone is seeking an order validating Dauman and Abrams' removal. That request was assigned to Judge David Cowan, who in May dismissed a lawsuit by an ex-girlfriend who claimed Sumner Redstone was mentally incompetent.

The outcome of the cases, and who ends up controlling the trust and the National Amusements board, will have wide-ranging implications for Viacom and CBS and could result in changes at the top of both companies, possibly through mergers and acquisitions.

(Reporting by Jessica Toonkel in New York; Additional reporting by Lisa Richwine in Los Angeles; Editing by Richard Chang)