NEW YORK — The purchase price of Kayser-Roth Corp. has been lowered by $63 million to $170 million because of a downturn in Kayser-Roth’s business.

Legwear Acquisition Corp., representing Grupo Synkro SA de CV and a group of Mexican investors, which agreed last November to acquire Kayser-Roth from Collins & Aikman Group Inc., said both companies agreed to amend the original deal, valued at $233 million, “in light of recent changes in Kayser-Roth Corp.’s operating performance.”

A spokesman representing Grupo Synkro declined to comment on Kayser-Roth’s operating results.

In addition to the $170 million purchase price, the new accord calls for a warrant to be given to the sellers to purchase a 10 percent equity in Legwear. The acquisition is expected to be completed by Jan. 28.

As reported, the transaction will result in a hosiery producer with combined sales estimated at $600 million.

Synkro, the largest producer and distributor of legwear in Mexico, had sales of $180 million in 1992, with women’s hosiery and men’s and women’s socks accounting for 77 percent of sales and 98 percent of operating profits.

The Mexican investment group comprises members of the Ballesteros family, principal stockholders in Grupo Synkro.

Kayser-Roth owns the No nonsense pantyhose brand, Burlington hosiery, and CK Calvin Klein hosiery. It also makes socks under the Burlington, Interwoven, Adler, and Gold Cup names.