A Viacom International suitor again raised its bid.

National Amusements Inc. raised the cash portion of its bid for Viacom International to $42.75 a share from $42 a share in a bid made Sunday. The preferred stock portion was raised to $7.75 from $7.50. Meanwhile, Oppenheimer & Co. said it has accumulated 7% of Viacom’s stock. But Oppenheimer said in a filing with the SEC that the purchases were solely for arbitrage purposes and that it has no interest in gaining control of the entertainment and communications firm.