Shares in aerospace giant Rolls-Royce led the FTSE higher, jumping 9% after its profits beat expectations.
The company reported a 12% rise in revenues to £7.57bn for the first six months of the year, helped by a 27% increase in large engine deliveries.
Rolls also said cost savings were ahead of schedule and it was on target to hit profit forecasts.
The company reported a first-half pre-tax profit of £1.94bn, compared with a £2.15bn loss a year earlier.
Underlying profits more than doubled to £287m, comfortably beating analysts’ forecasts.
By midday, Rolls-Royce was the biggest riser on the FTSE 100, with the index up 45.75 points at 7,417.75.
Intertek Group was another big riser, up 8.7%, after the product testing company said its half-year profits rose more than 20% to £210.3m.
Shares in Direct Line were up nearly 7% after the insurer reported a 9.5% increase in operating profits to £354.2m.
On the currency markets, the pound was unchanged against the dollar at $1.3216 and 0.2% higher against the euro at 1.1184 euros.