Stepping up its defense against a hostile takeover attempt by Kennecott Corp., Curtiss-Wright Corp. upped it's planned tender offer today for the repurchase of one million shares of its own stock from $44 to $46 a share.

The $46 tender offer, which the aerospace firm expects to begin on Monday, far exceeds the $40 a share that Kennecott has been offering in its attempt to acquire 49 percent of Cutriss-Wright stock. Kennecott's tender offer is scheduled to expire next Friday.

As a last Tuesday, Kennecott, the giant copper producer, had been able to acquire only about half the 4.1 million Curtiss-Wright shares it is seeking.

In the wake of Curtiss-Wright's announcement today, its stock opened trading on the New York Stock Exchange at 42 1/2, up 1 1/4 from wednesday's close.

The New Jersey-based aerospace company said the decision to increase the terms of the offer followed additional analysis and consultation with financial advisors.

Teledyne Inc., which holds about 2.6 million shares, or 31 percent of all outstanding Curtiss-Wright shares, has stated that it does not intend to tender any of its shares under the increased offer, Curtiss-Wright said.

Curtiss-Wright said Wednesday it would drop the condition that Kennecott Corp. not purchase more than 3.7 million Curtiss-Wright shares.

Curtiss-Wright said it had imposed the condition to preserve the opportunity to negotiate a tax-free merger with Kennecott, but added that the opportunity for a merger would continue to be available so long as Kennecott does not purchase an additional 1.6 million shares of Curtiss-Wright stock.