Britain's main share index edged higher on Friday, supported by gains in heavyweight bank HSBC after it said it is considering moving its headquarters out of Britain for regulatory reasons.

Shares in the London-based global bank rose 2.7 percent after it said its board had asked management to look at where is the best place to be based in light of new UK regulations, citing in particular the requirement to ringfence retail operations.

'There's a lot of uncertainty and operating costs to establishing a ringfence,' Mike Trippitt, an analyst at Numis Securities, said. 'The review is a step in the right direction.'

The stock added 12 points to the FTSE 100, which was up 26.73 points, or 0.4 percent, at 7,080.40 points at 0832 GMT. The index was up 1.3 percent since the start of the week.