Texas Air Corp. said former Continental Airlines shareholders have been offered an additional $3.75 a share over the previously announced settlement with the group . . . Joseph L. Harrosh of Fremont, Calif., who has a 5.7% stake in Bethlehem Steel's cumulative convertible preferred stock, said he may seek a seat on the company's board . . . Landover, Md.-based Dart Group Corp. said it is prepared to negotiate all terms of its proposed $1.62-billion acquisition of Supermarkets General Corp., Woodbridge, N.J., the nation's eighth-largest food retailer.