Sharecast - The top-flight index was steady 7,382.98.
Russ Mould, investment director at AJ Bell, said: "The market had been pinning hopes on a Chinese reopening to help ease global supply chain problems and kickstart growth in the world’s second largest economy.
"However, renewed outbreaks of Covid have seen some restrictions return and helped dampen sentiment, with oil prices also lower.
"Once again, the FTSE 100 is finding the 7,400 mark a difficult wall to climb over as nagging worries over the economic outlook help to drag it lower, with its heavy weighting to commodities stocks not helping given this sector is particularly sensitive to Chinese growth fluctuations."
In equity markets, online supermarket Ocado (LON:OCDO) was on the slide again.
Miners - which are heavily dependent on demand from China - were among the worst performers, with Glencore (LON:GLEN), Anglo American (LON:AAL) and Antofagasta (LON:ANTO) all down.
Elsewhere, catering group Compass fell even as it hiked its dividend and reported a rise in full-year underlying operating profit and revenues, hailing record net new business.
On the upside, Endeavour Mining gained after saying it had made a major discovery at its 100%-owned Tanda-Iguela greenfield exploration property in Côte d’Ivoire.
Virgin Money (LON:VM) rallied as it reported a strong rise in full-year profits driven by higher interest rates. The bank said pre-tax profit surged 43% to £595m. It also posted impairment losses of £52m, compared with a £131m credit a year ago.
Market Movers
FTSE 100 (UKX) 7,382.98 -0.03%
FTSE 250 (MCX) 19,356.39 0.38%
techMARK (TASX) 4,383.22 0.43%
FTSE 100 - Risers
BAE Systems (LON:BAES) (BA.) 785.00p 1.92%
Centrica (LON:CNA) 94.66p 1.78%
Endeavour Mining (EDV) 1,665.00p 1.52%
Imperial Brands (LON:IMB) 2,149.00p 1.32%
GSK (GSK) 1,386.00p 1.29%
HSBC Holdings (LON:HSBA) 485.05p 1.28%
British Land Company (BLND) 412.00p 1.23%
Relx plc (REL) 2,310.00p 1.18%
B&M European Value Retail S.A. (DI) (BME) 402.50p 1.16%
Unilever (LON:ULVR) 4,083.50p 1.06%
FTSE 100 - Fallers
Ocado Group (OCDO) 619.00p -8.73%
Harbour Energy (HBR) 316.20p -3.42%
Melrose Industries (LON:MRON) (MRO) 127.30p -2.68%
Prudential (LON:PRU) 954.20p -2.49%
Entain (LON:ENT) 1,309.00p -2.31%
Intermediate Capital Group (LON:ICP) 1,184.00p -2.19%
Associated British Foods (LON:ABF) 1,500.50p -2.18%
International Consolidated Airlines Group (LON:ICAG) SA (CDI) (IAG) 129.44p -2.07%
Smurfit Kappa Group (CDI) (SKG) 3,011.00p -1.86%
Halma (LON:HLMA) 2,185.00p -1.80%
FTSE 250 - Risers
Virgin Money UK (VMUK) 165.05p 13.36%
Balanced Commercial Property Trust Limited (BCPT) 91.00p 7.18%
PureTech Health (PRTC) 255.50p 6.46%
Baltic Classifieds Group (BCG) 149.60p 3.89%
Home Reit (HOME) 78.50p 3.84%
Hammerson (HMSO) 25.77p 3.74%
Bluefield Solar Income Fund Limited (BSIF) 140.50p 3.69%
NextEnergy Solar Fund Limited Red (NESF) 114.90p 3.51%
Kainos Group (KNOS) 1,642.00p 3.47%
TBC Bank Group (TBCG) 2,255.00p 3.44%
FTSE 250 - Fallers
Aston Martin Lagonda Global Holdings (AML) 121.30p -7.90%
RHI Magnesita N.V. (DI) (RHIM) 2,124.00p -5.43%
ASOS (LON:ASOS) (ASC) 670.50p -4.69%
International Distributions Services (IDS) 241.90p -4.12%
easyJet (LON:EZJ) 373.60p -3.69%
Shaftesbury (SHB) 378.00p -3.52%
Future (FUTR) 1,466.00p -3.36%
Molten Ventures (GROW) 435.60p -3.20%
Bodycote (BOY) 579.00p -3.10%
Ashmore Group (ASHM) 231.60p -2.77%