Sumner M. Redstone and his daughter, Shari E. Redstone, are feuding again, this time over Mr. Redstone’s efforts to renegotiate debt owed the Redstones’ movie theater company.

Sumner M. Redstone, the controlling shareholder of Viacom and CBS, said that he had sold his stake in Midway Games as his family’s holding company looks to get out from under $1.6 billion in debt.

Sumner M. Redstone, the controlling shareholder of Viacom and CBS, said that he had sold his stake in Midway Games as his family’s holding company looks to get out from under $1.6 billion in debt.

In order to stave off dismantling his media empire, Sumner M. Redstone, the controlling shareholder of Viacom and CBS, may sell his movie-theater chain.

Shari E. Redstone resigned as chairwoman of Midway Games to focus on refinancing efforts at National Amusements.

Sumner M. Redstone’s forced sale of more than $200 million in stock is the latest twist in a tumultuous decade for the Viacom chairman.

Viacom said it would end its program to buy Sumner M. Redstone’s shares at the same rate that it repurchased from public shareholders.

Shari Redstone and her father, Sumner M. Redstone, appear to be battling in public again — this time over a large sell-off of shares by the family company, National Amusements.

In an interview, Sumner M. Redstone, chairman of Viacom and CBS, said that his daughter was no longer the company’s heir apparent.

CBS said its television profit rose 15 percent, to $402 million, in part because of lower production costs during the strike by the Writers Guild of America.