NEW YORK (CNN/Money) - Northrop Grumman Corp., which has launched an unsolicited $5.9 billion hostile bid for TRW Inc., reiterated Tuesday that it would raise its offer but only if its gets a peek at TRW's books.

Los Angeles-based Northrop (NOC: Research, Estimates) said it is prepared to increase its offer if due diligence shows that a higher value is warranted. However, TRW's board must first allow Northrop to finish its due diligence.

"We believe that $47 per share is a full and fair value in combination with Northrop Grumman, but we are willing to be convinced otherwise and their board should want to do so," Northrop said in a statement.

In late February, Northrop offered to buy TRW, a Cleveland-based diversified manufacturer of parts for automobiles, satellites and other machinery, for $47 a share. Northrop went hostile with the offer after TRW's board unanimously rejected the bid as too low.

Analysts have said that Northrop has sought to take advantage of TRW's low share price after the company's CEO, David Cote, left to join Honeywell International Corp.

But Northrop Tuesday continued to maintain that if TRW (TRW: Research, Estimates) were truly intent on maximizing shareholder value, it would engage in discussions with a legitimate buyer. Northrop has asked TRW to allow it and any other qualified buyer access to the company's non-public financial data, so that it can determine whether to boost its $47 a share bid. Northrop also wants TRW to establish an independent committee to review any offer.