The London market built on Wednesday's record high, but shares in Merlin Entertainments fell despite it reporting a rise in profits.
Merlin - which operates theme parks such as Legoland and Alton Towers - reported pre-tax profits of £277m for 2016, up from £250m a year earlier.
The weak pound had led to more European tourists visiting its UK sites, which also include Madame Tussauds.
Despite this shares in Merlin were down 2.8% at 544p in early trade.
Shares in outsourcing group Capita fell 3.7% after it reported a fall in full-year profits and said its chief executive was stepping down.
That made it the biggest faller on the FTSE 100. However, the UK's benchmark was up in early trade, climbing 5.98 points to 7,388.88, as it built on the record closing high recorded in the previous session.
In the FTSE 250, shares in Travis Perkins fell 5.3% to £14.82 after the building materials company said full-year profits had fallen by two-thirds.
Profits last year sank to £73m from £224m in 2015 after the company wrote down the value of its plumbing, heating and tile businesses by £235m.
But shares in aerospace and defence firm Cobham rose 3.8% to 126.80p despite it announcing plans for a £500m rights issue.
The news came as the company reported pre-tax losses of £847.9m, compared with £39.8m the year before, after a series of hefty asset writedowns.
On the currency markets, the pound fell 0.1% against the US dollar to $1.2286 but rose 0.1% against the euro to 1.1663 euros.