The Comcast Corporation, the cable giant, has agreed to donate time valued at $51 million over three years.

The Comcast Corporation and other cable companies have similar plans, as do some broadcasters, after digital broadcasting begins in the fall.

The cable system was later sold to Comcast Corporation.

This summer, however, the Comcast Corporation announced an unsolicited bid to acquire the business for $44.5 billion.

The buyer was the Comcast Corporation, an operator of cable television systems there.

Microsoft last year invested $1 billion in another cable company, the Comcast Corporation.

Two years ago, the company invested $1 billion in the Comcast Corporation, one of the nation's biggest cable television companies.

The Comcast Corporation, the cable television giant, said it would buy back up to $500 million of its stock.

Last week's casualty may have been the Comcast Corporation, the big cable television operator.

Last December, it agreed to sell its cable television unit, the nation's biggest, to the Comcast Corporation.