• FTSE 100 down 0.3%, FTSE 250 dips 0.2%
• Global fears remain, U.S.-China talks eyed
• Mid-cap SIG plummets after profit warning

The main index, which shed more than 3.6% last week on fears of a global economic slowdown and the risk of a recession, gave up another 0.3% by 0707 GMT. The mid-cap FTSE 250 edged 0.2% lower.

Building materials supplier SIG tanked 26% after it forecast significantly lower annual profit in its specialist distribution and roofing merchanting businesses due to weaker construction activity in Germany and the UK.