A WING of Belfast-based Bombardier has been named as the preferred bidder for the single biggest piece of work to upgrade the London Underground.

The work is aimed at offering faster, more reliable trains, more often, on the Circle, District, Hammersmith -amp; City and Metropolitan lines.

The upgrade will deliver 65% more capacity on the Circle and Hammersmith -amp; City Lines, 27% on the Metropolitan and 24% on the District.

The news came amid more travel disruption on the London Underground.

Services on the Victoria, Jubilee and Piccadilly Lines were hit because of problems including faulty trains following disruption on the District Line which hit travellers on their way home from work earlier in the week.

London Underground managing director Mike Brown said: "This is a major step forward in our plan to upgrade the Tube and will mean faster, more frequent and reliable Tube services for Londoners.

"We insisted that those bidding for this contract found innovative ways to deliver the new signalling system without the need for the level of closures we have seen on other lines, and I'm pleased Bombardier have committed to that."

Bombardier, which manufactures planes and trains, is headquartered in Montreal, Canada and has based part of the Bombardier Aerospace division is based in east Belfast.

Bombardier Transportation has 59 production and engineering sites in 23 countries and more than 40 service centres across the world.