8 to 10 percent increase seen in local phone bills

The chairman of the American Telephone & Telegraph Company Monday predicted a rise of 8 to 10 per cent a year in average local telephone bills after the breakup of the telecommunications giant.

Charles Brown told the Senate Commerce Committee he expected average monthly bills, which are now about $10, to rise ''under one dollar'' to $11 a month the first year, and $12 a month the second.

This was his first prediction on local rates since the historic Jan. 8 agreement with the government requiring AT&T to divest itself of its 22 local telephone companies.

He said the accord itself could not be blamed for higher local bills, now subsidized by AT&T's long distance service. He said inflation, accounting changes, and new competition requiring new equipment would drive up local bills.