Despite these falls, the FTSE 100 is still up 25.61 points or 0.36% at 7106.62.
But the more domestically focused FTSE 250 has slipped back, down 0.42% at 22,662.94.
10.35am: Pharma firms ahead
Leading shares remain in positive territory, with the FTSE 100 up 19.77 points or 0.28% at 7100.78.
Pharmaceutical firms are adding to their recent gains and providing support for the index.
AstraZeneca PLC (LON:AZN) has added 127p or 1.56% to 8257p while GlaxoSmithKline PLC (LON:GSK) has climbed 20.20p or 1.46% to 1400.6p.
Auto Trader Group PLC (LON:AUTO) continues to lead the way, up 6.68% to 616.4p, with BT Group PLC (LON:BT.) close behind, 3.19% better at 189p.
But investors are still playing it cool ahead of the raft of inflation data coming up later.