After an initial drop which made it look like the FTSE 100 would continue its downward journey for a second day, the index rallied, led by Just Eat and BHP.
The index rose by 27.13 points, ending at 7,181, a 0.4% rise.
It came after the Anglo-Australian miner decided to become more Australian and less Anglo, shifting its dual-listed structure in a major revamp to how the business works.
The decision was welcomed by investors, who sent BHP’s shares to the top of the FTSE 100 on Tuesday.
The news could have wider ramifications for the London market – BHP is the world’s biggest miner and one of the biggest companies on the FTSE 100.
It will have to step away from the index after the move, something that will weaken the bond that sees the value of the FTSE drop when the pound gains, and vice versa, said Joshua Mahony, an analyst at IG.
The index is full of companies, like BHP, Rio Tinto and BP, which sell much of their products in dollars. When the price of a pound rises, it therefore makes the price of their shares fall.
Losing BHP will not reverse this but will likely dampen the effect.
Sterling on Tuesday stayed relatively flat against the dollar, but gained against the euro. One pound could buy 1.3741 dollars or 1.1732 euros by the end of the day.
After markets closed in Europe, the S&P 500 and Dow Jones in New York had both gained 0.8%. The Dax in Frankfurt closed down 0.1% and the Paris Cac dropped 0.3%.
Just Eat Takeaway.com’s shares were snipping at the heels of BHP. It closed up 2.9% after revealing that UK orders soared 75% to 135 million in the most recent six-month period.
Fulham Shore, which owns restaurant chains Franco Manca and Real Greek, said it is looking at 150 new sites for restaurants. Shares rose 1%.
BT’s shares dipped 1%. It chose former FA and ITV boss Adam Crozier as its new chairman on Tuesday.
The biggest risers on the FTSE 100 were BHP, up 77.5p to 2,358p, Just Eat Takeaway.com, up 176p to 6,310p, Rentokil, up 14.2p to 574.6p, Hikma, up 61p to 2,583p, and Scottish Mortgage Investment Trust, up 30.5p to 1,351p.
The biggest fallers on the FTSE 100 were IAG, down 5.24p to 159.22p, United Utilities, down 11.5p to 353.1p, Whitbread, down 76p to 3,024p, Johnson Matthey, down 65p to 2,952p, and Pearson, down 16p to 762p.