(Close): London shares ended Friday just 5 points higher, dragged down by the mining sector, as Marks and Spencer fell another 1%.
Shares in Marks and Spencer closed 4p lower at 386.5p – a 12% fall from the 440p they stood at before the retailer said on Wednesday that profits would fall under a turnaround plan.
The FTSE 100 closed 5 points higher at 6,270.79 points.
The index posted its biggest weekly gain for six weeks.
Royal Mail was the biggest riser on the blue-chip index, ending 2% higher at 532.5p.
Traders said the stock was helped by news that the Unite union had cancelled proposed strike action, as well as a report of a possible merger between Belgian and Dutch mail operators Bpost and PostNL.
Oil lost its gains made on Thursday with Brent crude trading at $49.21, down 0.8%.