The FTSE 100 fell 33 points (0.55 percent) to 5,831 by 15:00. The FTSE 250 slipped 120 points (1 percent) to 11,889 and the FTSE AIM 100 declined 16 points (0.4 percent) to 4,020.
Lloyds (LON:LLOY) led the blue chips, climbing 2.5 percent. Outsourcer Capita Group (LON:CPI) also did well, tacking on 1.6 percent. Temporary power provider Aggreko (LON:AGK) advanced 1 percent.
Specialty chemicals firm Johnson Matthey (LON:JMAT) was one of the heaviest fallers, sliding 4 percent.
Oil & gas
BP (LON:BP) fell 1.1 percent, while fellow supermajor Royal Dutch Shell (LON:RDSB) posted a small loss. BG Group (LON:BG), Cairn Energy (LON:CNE) and Tullow Oil (LON:TLW) shed just over 1 percent. Services company Wood Group (LON:WG) dropped 2.2 percent.
Midcaps followed. Salamander Energy (LON:SMDR) fell 4.5 percent. JKX Oil & Gas (LON:JKX) followed with a 3.4 percent loss. Premier Oil (LON:PMO) and Soco International (LON:SIA) lost 1.4 percent and 1 percent respectively.
Mining
Precious metals
Mining companies slipped into the red today. Lonmin (LON:LMI) slipped 4 percent. Lonmin (LON:LMI) and Randgold Resources (LON:RRS) shed 2 percent and 1 percent respectively.
Shares in African Barrick Gold (LON:ABG) slid 9 percent. Other FTSE 250 constituents Petropavlovsk (LON:POG) and Aquarius Platinum (LON:AQP) declined 3.5 percent and 2 percent respectively.
Eurasia Mining (LON:EUA) and Cluff Gold (LON:CLF) outperformed the sector, surging 7 percent and 6 percent respectively.
Base metals
Antofagasta (LON:ANTO) was the heaviest faller in the sector, slipping 4.5 percent. Kazakhmys (LON:KAZ) and Xstrata (LON:XTA) shed nearly 2.5 percent. BHP Billiton (LON:BLT) and Vedanta Resources (LON:VED) were down 2 percent. Anglo American (LON:AAL) fell 1.5 percent.
Banks, insurance, private equity
Lloyds (LON:LLOY) led the banks, rising 2.5 percent. Barclays (LON:BARC) added 1 percent. Standard Chartered (LON:STAN) was down 1 percent.
Insurers Old Mutual (LON:OML) and Prudential (LON:PRU) dipped 1 percent.Small cap movers
Other notable risers among the small caps included virtual queuing specialist Lo-Q (LON:LOQ), which added 5.5 percent.