Sainsbury's shares also slipped on the possibility it could suffer its first like-for-like sales fall in more than nine years.
Overall, the FTSE-100 Index was flat as traders kept their powder dry ahead of corporate news later in the week, closing just 0.1 point up at 6730.7.
Germany's Dax was also flat while France's Cac 40 fell amid data indicating continued underperformance in its services sector. In New York, lacklustre US economic data saw the Dow Jones Industrial Average in the red too. On currency markets, sterling was flat at 1.64 US dollars and 1.20 euros.
In London, equities were held back by weaker mining stocks as Fresnillo dipped 36p to 735.5p, Antofagasta dropped 34p to 787p and Randgold Resources was 138p off at 3786p, with Rio Tinto sliding 104p to 3266p.
The top-flight risers' board was led by RSA Insurance, which jumped 6% on hopes that it will soon be able to draw a line under the accounting issues that have blighted its Irish business in recent weeks.
Shares in the More Than owner, which is currently without a chief executive following the resignation of Simon Lee last month, leapt 5.8p to 97.9p.
Travel stocks also did well, with British Airways owner International Airlines Group up 6.2p to 414p and easyJet 32p stronger at 1597p. Both companies doubled in value during 2013 as conditions in the sector showed signs of stabilising.
In the retail sector, shares in supermarket chain Tesco enjoyed a positive session, up 1.7p to 332.2p ahead of trading figures on Thursday which are sure to be another key test for chief executive Philip Clarke's £1 billion turnaround plan.
In contrast, M&S shares declined 3.7p to 440.3p amid speculation that clothing and homewares sales dropped by up to 1.5% over the festive trading quarter, in spite of discounts of up to 30%.
Even takings from the food department, which has performed strongly amid the woes of the fashion division, may fail to provide cheer. Credit Suisse predicts like-for-like growth for the period will have slipped to 1.5%, from 2.5% in the second quarter.
Meanwhile, Sainsbury's, which publishes third quarter figures tomorrow, is expected to lose its record for underlying sales increases, with analysts pencilling in a decline after 35 quarters of growth in a row. Shares slipped 6.2p to 367.8p.
The biggest FTSE-100 risers were RSA, up 5.8p to 97.9p, Hargreaves Lansdown up 50p to 1491p, Persimmon up 31p to 1290p and easyJet up 32p to 1597p.
The biggest FTSE-100 fallers were Fresnillo down 36p to 735.5p, Antofagasta down 34p to 787p, Randgold Resources down 138p to 3786p and Rio Tinto down 104p to 3266p.