Curtiss-Wright Corp., said that, if it wins a proxy battle to gain control of Kennecott Copper Corp., it plans to have Kennecott offer to buy in half of its $33.2 million outstanding shares at $40 each. Yesterday Kennecott stock closed at $26.88, up $1.37 for the day.

The disclosure by Curtiss-Wright, which owns 9.9 percent of Kennecott, was made in a prozy statement being sent to Kennecott shareholders that the Securities and Exchange Commissioner cleared yesterday.

Curtiss-Wright earlier had indicated that is plans to sell Carborundum Corp., which Kennecott acquired several months ago for $567 million, if it wins the proxu fight, and to distribute the proceeds to shareholders. The buy-offer appears to be a further sweetener to get Kennecott shareholders to back Curtiss-Wright's insurgent slate of 17 directors.

In its proxy statement, Curtiss-Wright said it would try to sell Carborundum "at an advantegeous price," but said there was no guarantee that it would equal or even approach the $567 million Kennecott paid for the company. It did note that several other companies had expressed interest in Carborundum at "not more than $2 to $3 below the $66 Kennecott paid" for each share.

To buy in 16.6 million shares at $40 each would require $664 million. In addition to the potential proceeds from a Carborundum sale, Curtiss-Wright said it believes additional funds could be provided from Kennecott's cash and marketable securities and from borrowinf against the $400 million principal amount of 30-year subordinated income noted Kennecott receivved when it sold the Peabody Coal Co., last year.

"The nominees believe, accordingly, that it be possible to make available sufficient funds for Kennecott either to make a pro rata distribution of approximately $20 with respect to each Kennecott share or to make a tender offer to its shareholders for 50 percent of the outstanding shares at a price of approximately $40 per share," according to the proxy statement Curtiss-Wright indicated it would seek the latter course.

Kennecott, whichearlier this week defended its purchase of Carborundum in a letter to its shareholders and in full-page newspaper ads, had no comment on the proxy statement. Kennecott's annual meeting is scheduled for May 2 when the showdown will take place.

Curtiss-Wright Chairman T. Roland Berner, who is the chief strategist in the proxy battle, with hold a news conference in New York this morning.