British retailer Marks & Spencer reported strong Christmas sales, with a better-than-expected increase in like-for-like food sales of 6.3% delivering its best ever market share, and a 8.6% rise in clothing and home sales.

Chief Executive Stuart Machin said M&S outperformed the market in food in both volume and value in the four-week Christmas period for the second year running, whilst it maintained market leadership in clothing and home with its highest share in seven years.

"This performance across both our businesses provides confidence in delivering our full-year results," he said on Thursday.

International sales increased 12.5% at constant currency, with a strong performance in key franchise markets in the Middle East and owned markets including India in the 13 weeks to Dec. 31.

"There are clear macro-economic headwinds ahead and underlying cost pressures, but our strong trading performance provides confidence that the results for the year will be consistent with the guidance set out at the group's interim results in November," it said. (Reporting by Paul Sandle; Editing by Kate Holton)