The benchmark FTSE 100 index was down 0.3% by 0705 GMT.
Oil majors Shell and BP declined more than 1% each, while miners fell 0.4%, tracking weakness in commodity prices on fears that an expected U.S. interest rate hike this week will dampen demand. [O/R] [MET/L]
The domestically focussed mid-cap index slid 0.3%.
In company news, SThree rose 4.5% after posting a 58% surge in its half-year operating profit, supported by strong hiring demand and as people move jobs in a competitive market.
Mobile and broadband group Vodafone slipped 0.4% after reporting a drop in first-quarter service revenue in its largest market, Germany, reflecting broadband and TV losses in the second half of its last financial year after regulation changes.
Serica Energy gained 2.4% after it rejected a revised merger proposal again from energy investment firm Kistos, which valued the British oil and gas group at nearly 1.2 billion pounds ($1.44 billion). Kistos fell 2.4%.
(Reporting by Bansari Mayur Kamdar; Editing by Vinay Dwivedi)
