Infrastructure firm Balfour Beatty has won a £170m contract to upgrade baggage screening and handling systems for Heathrow Airport.
The project will involve upgrading and installing baggage screening and handling systems at Heathrow's eastern baggage facility.
The company's share price fell 2.03 per cent in early trading.
Balfour Beatty boss Leo Quinn said: "This contract award is testament to the strength of the partnership we have developed with Heathrow Airport Limited over the last 17 years.
"The UK aviation sector is a core market for Balfour Beatty and we are delighted to play our part in helping Heathrow maintain its position as a leading travel hub and supporting local employment."
Balfour Beatty is nearing the final stages of a 24-month turnaround plan, implemented by Quinn when he joined the firm in 2014. He was brought in to improve the company's fortunes, after a series of profit warnings.
Earlier this year, the group was named as one of 13 companies helping Transport for London to expand its property empire.
Meanwhile, Heathrow is still waiting for a decision on its proposed third runway - and the government said last week that an announcement would be delayed again, until "at least October".