Supermarket group J. Sainsbury , the subject of a 10.6 billion pound proposed bid, saw its growth slow in the second quarter as the country's wettest summer on record dampened spending. Sales at its stores open at least a year rose 3.1 percent excluding fuel in the 16 weeks to October 6, slowing from 5.1 percent growth in the first quarter. In what could be Sainsbury's last quarterly trading update as a listed company, total sales excluding fuel rose 4.7 percent, broadly in line with analyst expectations.