The FTSE 100 was 0.2 percent lower, lagging its European and Asian counterparts, while the FTSE 250 added 0.2 percent by 0817 GMT.
Office group IWG pushed midcaps higher after divestiture plans for its Japan business
Miners, which last week scaled seven-year highs, handed back some of those gains with a 0.8 percent dip.
CMC Markets analyst David Madden said there did not appear to be any major shift in sentiment, and copper prices rose as data from China showed higher unwrought copper imports in March, and supply concerns and hopes of a U.S.-China trade resolution also gave support.
Weighing further on the index were exporter stocks, which slipped as sterling strengthened. AstraZeneca, Reckitt Benckiser and GlaxoSmithKline dipped by around 1 percent.
The pound's gains followed upbeat comments from Britain's foreign minister Jeremy Hunt on talks between the government and the opposition Labour Party to find a consensus over Brexit.
Shell and BP extended losses following a dip in oil prices.
Compass Group, the world's biggest catering firm, was on track for its worst day in six months with a 3 percent drop after Barclays cut its rating.
Financials inched toward a six-month high, lifted by last week's upbeat results from U.S. bellwethers JP Morgan and Wells Fargo, and strong bank loan data from China.
"Traders will be keeping a close eye on ... whether the strong start (to U.S. earnings) is able to continue beyond the banking sector ... right now this is looking unlikely," London Capital Group analyst Jasper Lawler said.
Lloyds, Prudential and Barclays were among the best blue-chip performers.
Among midcaps, serviced office space provider IWG surged 17.7 percent to a two-year high after plans to sell its Japanese operations for 320 million pounds and a double upgrade from Credit Suisse on the stock.
Mediterranean-focused Energean Oil & Gas jumped almost 10 percent to a record high after announcing a new gas discovery at the Karish North exploration well.
Builder Kier added nearly 4.1 percent as it said its newly appointed CEO planned to cut debt and respond to problems affecting the outsourcing industry.