Markets 'pretty calm' as UK delivers Article 50 letter to European Union
London's blue chip index pushed higher and sterling rates were mixed, as markets largely shrugged off the well-flagged triggering of Article 50.
The pound rose 0.1% versus the euro to 1.153, but fell 0.4% against the US dollar to 1.240, dropping back from initial gains made in the wake of Theresa May's address to Parliament this afternoon.
The FTSE 100 ended the day higher by 0.4% or 30.30 points at 7,373.72, thanks in part to the ease in the pound.
It came after the Prime Minister Theresa May sent a letter to European Council president Donald Tusk, formally triggering the two-year process of UK withdrawal from the European Union.
Neil Wilson, a senior market analyst at ETX Capital said: "The countdown to Brexit has begun but by and large markets shrugged off the triggering of Article 50.
"Stocks and the pound took the momentous decision in their stride, largely as expected as Brexit was already priced in.
"We might have expected a touch more volatility as the UK delivered the letter but markets were pretty calm."
Across Europe, Germany's Dax and French Cac 40 both rose around 0.4%.
The price of oil was climbing as armed protesters blocked the western Libyan oil fields of Sharara and Wafa, disrupting supply. Brent crude was up 1.7% to 52.21 US dollars a barrel (£42.10).
In UK stocks, London Stock Exchange Group was one of the biggest risers, up 82p to 3,106p, after European regulators torpedoed its £21 billion merger with Deutsche Borse, saying the two exchanges failed to address competition concerns.
The move comes after the LSE rejected the commission's request last month to offload its 60% stake in the Italian trading platform MTS.
Mining giant BHP Billiton was close behind, rising 33p to 1,260p, after saying it was well positioned to boost value and returns from its western Australia iron ore operation.
In a contrast of fortunes, travel giant Tui Group sank into the red, down 12p to 1,123p, despite summer holiday bookings meeting expectations.
The Thomson owner said British sun-seekers were snapping up more long-haul holidays and cruises as concern over terrorist attacks and political turmoil continue to blight markets in Turkey and North Africa.
Away from the top tier, Flybe Group shares slipped 0.5p to 42.5p.
The airline said profits would take a £5 million to £10 million hit due to a major systems upgrade designed to bolster online sales and improve customer experience.
It comes as the company struggles with slowing demand and a spate of cancelled flights.
The biggest risers on the FTSE 100 were 3I Group up 40p to 740.5p, London Stock Exchange Group up 82p to 3,106p, BHP Billiton up 33p to 1,260p, and Antofagasta up 17.5p to 816p.
The biggest fallers on the FTSE 100 were Fresnillo down 27p to 1,535p, Standard Life down 5.8p to 354.4p, Randgold Resources down 115p to 7,055p, and RSA Insurance Group down 7p to 586p.