J Sainsbury reports very decent first-quarter sales against tough multiyear comparisons, Shore Capital analyst Clive Black writes. Performance in its core grocery unit were particularly good, he adds. As expected the British grocer backs its full-year guidance but the bottom end of its underlying operating profit outlook, which stands at 975 million pounds, could be raised at a later date, he adds. Shares closed Monday up 0.1% at 315.80 pence. (adam.whittaker@wsj.com)