Cablevision Systems Corp. on Monday unveiled two high-end services that provide Internet download speeds as fast as 50 megabytes per second.

In addition, all basic subscribers of its Optimum Online service would get bumped to download speeds15 Mbps and an upload speed of 2 Mbps. Subscribers had been receiving 10 Mbps and 1Mbps, respectively, officials with the Bethpage, N.Y., company said. The boost is at no additional charge.

The two new premium services include one with downloads of 30 Mbps and upload speeds of 2 Mbps. The "ultra" service provides upload and download speeds up to 50 Mbps.

The move is to improve the company's delivery of more advanced video, data and voice products, Tom Rutledge, chief operation officer for Cablevision, said.

"Our two new high-end data services, as well as a very significant speed increase for all customers at no additional charge, are direct results of Cablevision's investment in this high-capacity platform," Rutledge said in a statement.

Cablevision, which had more than 1.5 million customers as of June 30, plans to have the 30 Mbps service and the accelerated basic service available across the company's service area by the middle of 2006. The highest premium service is available now.

Pricing for the lower end premium service will cost an additional $9.95 a month for subscribers of Cablevision's Internet telephony service. By itself, the broadband service would cost an additional $14.95 a month.