The FTSE 100 shed 0.2% and the FTSE 250 was roughly flat by 0704 GMT.
An index of UK banks, which has been under pressure this week after protests in Hong Kong against a Chinese extradition bill, slipped for the fourth straight session.
The dollar was also subdued ahead of a key U.S. Federal reserve meeting next week where investors are expecting an interest rate cut, hitting exporters such as BAT.
Precious metals like gold were in demand as a result. Miner Fresnillo added 1.6%.
Small-cap SThree, which hires workforce for financial, energy, banking and pharmaceutical companies, gained 4% as its net fees rose due to strength in its international markets.