Britain's unseasonably warm autumn weather has taken its toll on Marks & Spencer, with the company today reporting a 13th quarterly fall in underlying non-food sales in a row. 

But the 130-year-old group did post a rise in underlying first-half profit for the first time in four years, beating expectations as it benefited from improved margins as well as a good performance in food. 

Marc Bolland, chief executive since 2010, has spent over £2.3 billion to address decades of under-investment, overseeing the revamp of products, stores, a website and marketing. 

He said the group is improving "step by step" but a new clothing team he set up in 2012 has so far failed to deliver a sustained increase in sales.

For the first time, M&S earned less in the year to the end of March than faster-growing rival Next. 

Britain's biggest clothing retailer by revenue said today that sales of non-food products, spanning clothing, footwear and homewares, at stores open over a year fell 4% in the 13 weeks to September 27, its fiscal second quarter. 

That compared with analysts' average forecast of down 3.7% and a first quarter decline of 1.5%. 

M&S said "unseasonal conditions" in September adversely impacted its first-half sales by about 1.3%. Mild autumn temperatures are not helpful for shifting high-margin winter coats, knitwear and boots. 

M&S's food business, which contributes over half of group sales, is performing better than clothing. Its sales on the same basis rose 0.2% - in line with analysts' forecasts. 

The group's online sales fell 4.6% in the second quarter having fallen 8.1% in the first quarter. 

The company said its first-half profit before tax before one-off items was £268m, ahead of analysts' average forecast of £252m and up from £262m last year. The interim dividend was raised by 0.2 pence to 6.4 pence.