J Sainsbury PLC (LSE:SBRY) backed its full-year outlook despite reporting a slowdown in sales growth over Christmas. “We have outperformed the market every week of this financial year and delivered volume growth ahead of the market for a fourth consecutive Christmas,” the FTSE 100-listed firm said. The food retailer said said third quarter grocery sales rose 9.3% although this rate eased to 8.6% in the six weeks to January 6 with stronger volumes offsetting lower inflation. Total retail sales rose 6.5% in t ...