Northrop Grumman announced yesterday it is upping its offer for TRW to encourage the company to allow Northrop to view its accounting ledgers. Northrop Grumman is now offering $53 for shares of TRW stock, according to an April 14 announcement. The company also said it is extending its pending exchange offer to May 3, 2002, at midnight Eastern time. "We are increasing our offer for TRW due to improving economic conditions which drive TRW's end markets and continuing positive developments...