The FTSE 100 closed 25 points, or 0.35%, higher at 7,404, after ITV announced its new chief executive.
Shares in ITV rose 1.3% after the broadcaster said it had appointed EasyJet's boss Carolyn McCall.
ITV's previous chief executive, Adam Crozier, left in June, but Ms McCall will not take up her new post until January next year.
Carillion shares leapt 19% on the news it was part of a consortium granted HS2 contracts by the government.
Carillion, in the wider FTSE 250, announced on Monday that it had appointed the accountants EY to support its strategic review, which has been launched after it issued a profit warning last week and announced the departure of its chief executive.
Carillion's shares were trading at about 67p, although this was still well below the 191p level they stood at prior to last week's profit warning.
Staying in the FTSE 250, shares in Weir Group rose 8% after the company, which makes pipes and valves for the energy and mining sectors, said revenue and operating profit for the full-year were set to beat expectations.
Weir said it been helped by a faster than expected recovery in the North American oil and gas markets.
The FTSE 250 index closed 112 points, or 0.6%, higher at 19,520.
The pound weakened slightly against both the dollar and the euro.
The pound fell 0.3% versus the US dollar to $1.31; sterling was also 0.3% down against the euro at 1.14 euros.