PROFESSOR LIFTS BANC TEXAS <BTX> PREFERRED STAKE A University of Massachusetts finance professor said he raised his stake in Banc Texas Group Inc to 45,340 shares of 1.4625 dlr cumulative preferred stock, or 7.4 pct of the total, from 30,300 shares, or 5.0 pct. In a filing with the Securities and Exchange Commission, Ben Shirley Branch also said he bought 52,025 shares of Class A cumulative convertible preferred stock, or 5.9 pct of the total, for 160,000 dlrs, bringing his total investment in both preferred series to about 330,000 dlrs. Branch said he bought the stock as an investment, but reserved the right to try to influence the company.