The FTSE 250 index was down 20.12 points, or 0.12%, to 17,041.85 mid-trading Thursday afternoon.
Leading the risers was online grocery delivery company Ocado Group, which surged today on the back of positive notes from Morgan Stanley and Deutsche Bank.
Vehicle hire group Northgate revealed it was on track to meets its annual targets for the financial year to March 2016, and it was making progress on its strategic plans.
The market also reacted positively to news that Serco has agreed the sale of its offshore private sector Business Process Outsourcing operations to private equity funds managed by Blackstone for around £250m. Chief executive officer Rupert Soames said the disposal will strengthen the balance sheet and enable the company to focus on its five core markets.
Rounding out the top ten movers was Allied Minds, which announced the formation of HawkEye 360 - a project that will use a constellation of small satellites in low Earth orbit to detect wireless signals that can be used to track and monitor global transportation networks, assist with emergencies, as well as other data analytics and reporting services.
Technology product distributor Premier Farnell took a big hit after reporting a 13.7% fall in interim pre-tax profits to £30.6m. It also warned that slowing momentum would mean the company's second half operating profits coming in at lower than forecasts.
Rotork also fell after Investec downgraded the stock to a 'sell' when the company warned its full year profits would be lower than expected.
FTSE 250 - Risers
Ocado Group (OCDO) 346.80p +8.54%
Northgate (NTG) 492.10p +5.71%
Serco Group (SRP) 109.80p +3.78%
Centamin (DI) (CEY) 62.35p +2.55%
Jimmy Choo (CHOO) 151.00p +2.51%
IP Group (IPO) 252.00p +2.44%
Kaz Minerals (KAZ) 159.60p +1.98%
Foxtons Group (FOXT) 240.50p +1.91%
Just Retirement Group (JRG) 186.70p +1.85%
Allied Minds (ALM) 485.50p +1.78%
FTSE 250 - Fallers
Premier Farnell (PFL) 114.00p -14.48%
Rotork (ROR) 194.30p -10.05%
Hunting (HTG) 434.40p -7.79%
Kier Group (KIE) 1,411.00p -4.40%
Petrofac Ltd. (PFC) 811.00p -4.25%
Zoopla Property Group (WI) (ZPLA) 208.40p -3.96%
Interserve (IRV) 583.00p -3.16%
Electrocomponents (ECM) 182.40p -2.82%
Lonmin (LMI) 22.18p -2.72%
IMI (IMI) 1,051.00p -2.69%