NEW YORK (CNN/Money) - Shareholders of TRW Inc. rejected a takeover proposal by Northrop Grumman Corp. that would have allowed the defense contractor to proceed with its $6.7 billion hostile bid, equal to $53 a share.

Based on the number of proxies submitted to independent inspector IVS Associates, shareholders apparently rejected the proposal that would allow Northrop to acquire more than 20 percent of the company, TRW said in a statement. In Ohio, companies are prevented by statute from buying more than 20 percent of a target unless shareholders allow it.

Certified results will be provided in the near future, TRW said.

The board of TRW (TRW: Research, Estimates), which has put itself up for sale, has already rejected the unsolicited offer from Northrop. But representatives from TRW and Northrop met late Thursday to discuss a condition contained in a confidentiality agreement required by TRW for any interested bidders.

Northrop (NOC: Research, Estimates) has balked at signing the agreement because of the standstill that would prevent it from pursuing a hostile bid should TRW choose another suitor.

"We had a very constructive discussion regarding the confidentiality agreement," TRW Chairman Philip Odeen said. "If Northrop wishes to proceed, I am confident that we can reach a mutually acceptable agreement."

Los Angeles-based Northrop, a defense contractor, initially offered $47 a share, or $5.9 billion, for TRW in February. After that effort was rebuffed, Northrop then raised its offer to $53 a share, or $6.7 billion, in April.

TRW's board rejected both offers, claiming the proposals were inadequate.

TRW is a manufacturing conglomerate whose products include auto parts and equipment for airplanes and spacecraft. Last week, the Cleveland-based company said it had entered into confidentiality agreements with several interested parties but not Northrop.

TRW has also said that it is in the process of selling its aeronautics business, which is valued at about $1 billion

Northrop on Friday said will not know the final outcome of the vote for several weeks. The company's current exchange offer to acquire TRW stock will expire at midnight.

"We will review our options over the weekend and issue a release Monday morning," Chairman and CEO Kent Kresa said in a statement. A Northrop spokesman declined further comment.

Shares of Northrop dropped nearly 3 percent in early afternoon trading Friday while TRW's fell marginally.