Blue chip shares struggled for direction following mixed data on Britain's jobs growth.
The number of people unemployed fell by 45,000 to 1.56 million in the three months to February, said official figures.
The FTSE 100 Index slipped 6.4 points to 7359.1, as the ONS data showed that average weekly earnings for employees rose by 2.2% excluding bonuses, compared with a year ago.
However, figures released earlier in the week by the ONS showed that inflation stood slightly higher at 2.3% in March. The FTSE 250 Index lifted 65.3 points to 19371.8.
In the top flight, shares in Tesco were lower after it reported a fall in annual profit after the retailer was fined for overstating its profits in 2014.
The supermarket giant said its full-year pre-tax profit, which includes a £235m charge after it agreed a deferred prosecution with regulators last month, fell to £145m from £202m the year before.
IG chief market analyst Chris Beauchamp said: "With real wage growth in Britain now lower than inflation the supermarkets will struggle to boost margins through price increases, and with consumers perhaps beginning to shop around for bargains again a new price war looms."
Tesco shares were more than 5% lower, or 10.5p at 185.1p, Sainsbury's was down 6p to 259.1p, while Morrisons fell 1.6p to 232p.
The biggest afternoon risers in the FTSE 100 Index were Rolls-Royce (+25.5p to 836p), Mediclinic International (+14p to 737.5p), Reckitt Benckiser (+121p to 7512p), Convatec Group (+4.4p to 288.8p) and BAE Systems (+9p to 650.5p).
The biggest afternoon fallers in the FTSE 100 Index were Tesco (-10.5p at 185.1p), Rio Tinto (-103p to 3172.5p), BHP Billiton (-33.5p to 1281p), Sainsbury's (-6p to 259.1p) and Antofagasta (-16p to 832.5p).
The biggest afternoon risers in the FTSE 250 Index were Pagegroup (+30.6p to 474.5p), Hays (+6.3p to 169p), Ibstock (+7.5p to 207.8p), JD Sports Fashion (+14.4p to 454.5p) and Meggitt (+13.6p to 460.5p).
The biggest afternoon fallers in the FTSE 250 Index were Booker Group (-10p to 192.2p), Vedanta Resources (-37p to 781p), Evraz (-8.6p to 218.7p), Ferrexpo (-6.3p to 161.4p) and Homeserve (-16p to 630p).