Metromedia and Southwestern amended a deal.

The two companies said they agreed to cancel the sale of Metromedia’s cellular telephone interests in New York, Philadelphia and Dallas to Southwestern Bell, knocking $453 million off the value of their $1.65-billion deal. Metromedia was unable to consummate that portion of the deal because its contracts with its partners in the three cities somehow prevented it from selling its interests there, Southwestern Bell spokeswoman Hilda Besand said. The original agreement called for Southwestern Bell to acquire cellular and paging properties from Metromedia in 19 cities.