Security Pacific Corp. said securities analysts' forecasts of a 5% to 10% increase in its second-quarter profits are "reasonable" . . . Standard & Poor's said it had lowered its rating of U.S. Steel Corp.'s senior debt to BBB- from BBB, the lowest ranking in S&P's four categories of investment-grade securities . . . Lufthansa reported that it has agreed to purchase six Boeing 747-400 jumbo jets and spare parts, a package worth about $800 million . . . Musicland Group said it has completed its acquisition of 60 music and home entertainment retail stores from Record Bar Inc. of Durham, N.C., and its unit, Licorice Pizza Inc. of Glendale.