The FTSE 100 ended down 55.78 at 5974.54 points, with Anglo American the biggest loser.
Shares in British Gas owner, Centrica, were the best performer, rising through the day to end up 7% after its drop in profit was smaller than expected.
Shares in defence group BAE Systems rose 1.3% as the company forecast earnings growth of up to 10% in 2016.
On the wider market, Tullow Oil tumbled 11%. after the oil producer said there could be an issue with a storage vessel at its flagship Jubilee field in Ghana.
On the currency markets, the pound was up 0.18% against the dollar at $1.4318, while against the euro, it was 0.5% higher at â‚¬1.2911.

Border Force officers found 19 Albanians and one Syrian hidden in a trailer carrying machinery at North Shields ferry terminal in 2015.
The HGV driver, Marek Niedzwiecki, 33, was jailed for five years at Newcastle Crown Court.
Accomplices Ferdinand Gjolla and Armando Mekolli were jailed for eight and three years respectively.
All three were found guilty of conspiring to facilitate unlawful entry into the UK following a 13-day trial.
The Home Office said officers inspected Polish national Niedzwiecki's lorry when it arrived from Ijmuiden, Holland, on 1 September 2015.
Their investigation led them to the home in Redhill Avenue, Barnsley, of Albanian national Gjolla, 41.
The Home Office said Gjolla was the main organiser while Niedzwiecki, an HGV driver, was responsible for transporting the people into the UK, and Mekolli, 30, assisted Gjolla with the transportation of them once they arrived in the UK.
Rachael Luther, from the Immigration Enforcement Criminal Investigations team, said: "This was a well-run organised crime group motivated by money.
"Their sole aim was to breach the UK's immigration controls and bring people into the UK illegally."
Of the 20 people found in the back of the lorry, 16 have been returned to Albania.
The Home Office said the cases of the remaining four are being progressed in line with the immigration rules.

The 33-year-old takes over the role from Charlotte Burton, whom he assisted last season alongside his coaching commitments at Brighton College.
Seamer Anyon took 199 wickets in 63 first-class appearances for Sussex between 2010 and 2014 and retired last year because of a knee injury.
He will also coach the women's under-19 and under-21 sides.
"This is a great opportunity to continue working with Sussex," he said.
"The women's game is fast-growing and I am looking forward to bringing my own experiences from professional cricket and using them to help the girls."
Alexia Walker, Sussex's most-capped women's player and coach of the under-17 side, will take on roles with the senior, under-21 and under-19 sides.
(Close): London's main share market closed lower on Thursday, dragged down by oil and mining companies
[NEXT_CONCEPT]
Three men who tried to smuggle 20 people into the UK in a lorry have been jailed.
[NEXT_CONCEPT]
Sussex have appointed former player James Anyon as head coach of their women's side.