SECURITIES

Shearson to Take Charge for Bad Loan: Shearson Lehman Bros. Inc. said it will take an additional charge against earnings of $40 million to $45 million in the current quarter to pay for a bad loan to Prime Computer Inc. The pretax charge comes on top of a $137-million pretax charge taken in the second quarter. The new charge is due to a reduced offering price for shares in Prime, based in Natick, Mass. Reduced income from the offering means that Shearson will recoup less of the 4-year-old loan to Prime. Prime got a $500-million temporary bridge loan from Shearson in 1988 to help finance a leveraged buyout by J. H. Whitney & Co.