The FTSE 100 was roughly flat, while the mid-cap FTSE 250 added 0.4% by 0710 GMT.

Uncertainty over whether any signs of progress towards a resolution of Washington and Beijing's trade war would emerge kept activity among most major sectors muted in early dealings.

Legoland operator Merlin Entertainments jumped 14.2% to 451 pence on the mid-cap index after agreeing to be acquired by the investment vehicle of Lego's founding family and Blackstone in a 455 pence a share deal.