UK's FTSE 100 slips at open; BT surges as Drahi raises stake

The internationally-focused FTSE 100 however shed 0.2% as caution gripped investors amid the ongoing U.S. debt ceiling talks. The mid-cap FTSE 250 dropped 0.1%, hit by a 3.6% fall in shares of Pennon Group Plc after water industry regulator Ofwat said it has started an enforcement investigation into the water firm's leakage performance. SSP Group Plc climbed 4.9% after the snack chain forecast annual profit at the upper end of its expectations.

UK's FTSE 100 slipped on Tuesday as uncertainties surrounding the U.S. debt deal weighed on sentiment, but BT Group rose after billionaire Patrick Drahi raised his stake in the telecom giant.

BT rose 1.8% after Drahi increased his stake in the company to 24.5% but restated his position that he does not intend to make a full takeover. The internationally-focused FTSE 100 however shed 0.2% as caution gripped investors amid the ongoing U.S. debt ceiling talks.

The mid-cap FTSE 250 dropped 0.1%, hit by a 3.6% fall in shares of Pennon Group Plc after water industry regulator Ofwat said it has started an enforcement investigation into the water firm's leakage performance. The broader utilities sector fell 0.8%.

Cranswick Plc added 2.0% after the meat producer reported a rise in annual profit benefiting from strong demand. SSP Group Plc climbed 4.9% after the snack chain forecast annual profit at the upper end of its expectations.