Maryland Attorney General Stephen H. Sachs asked for an injunction yesterday to keep the Woolco discount chain from boosting prices during the going-out-of-business sales now under way at its nine locations in Maryland. A hearing is set for Jan. 6.

Last week, Fairfax County officials announced that Woolco had signed an agreement to reduce prices on items that were not discounted as much as advertised and to refund money to customers who had overpaid during the sales. That agreement applied to the three Woolco stores in Fairfax County.

Maryland officials filed suit after failing to negotiate a settlement. The petition charged Woolco has "engaged in unfair and deceptive trade practices" by "representing that goods were 30 percent off Woolco discount prices when these representations were not in fact true."

In one affidavit accompanying the suit, Victor J. Trimarchi of Oxon Hill said he and his wife found a blender priced at $29.97 at the Woolco store in Clinton on Nov. 20, two days before the sale began. When the couple returned on Nov. 22 -- the first day of the sale -- to purchase the blender, they found its price had been raised to $37.97, the affidavit said.

Woolco attorney Robert Cahill said it would be improper for him to comment until he has read the suit and filed an answer for the company.