$3.5 billion offer for the portion of ADT Ltd. it doesn't own.

Under the latest offer, ADT shareholders would also get $12.50 in Western Resources stock for each ADT share, or 0.41322 of a share, based on Friday's closing price of 301 . ADT shareholders won't receive more than 0.42017 of a Western Resources share for each ADT share, Western Resource said.

The earlier offer had been for $7.50 a share in cash and $15 in Western Resources stock for about 73 percent of Bermuda-based ADT.

Topeka, Kansas-based Western Resources also said it plans to sell the Miami-based security systems and services company's auto auction business. It expects the sale would result in about $450 million in after-tax proceeds, based on a sale price of about $500 million.