Britain sets out plan for third runway at London's Heathrow

LONDON, Feb 2 (Reuters) - Britain is to lay out its proposals for a third runway at London's Heathrow airport on Thursday, launching a public consultation on a big infrastructure project the government sees as key to its post-Brexit future.

The government backed a $22 billion expansion of Heathrow in October to end 25 years of indecision with an ambitious plan to boost global trade links following the vote to leave the European Union.

While the government says the new runway is vital for the economy and businesses, critics are concerned over the impact on local residents and the environment.

A policy statement will set out what planning regulations the proposed runway will need to meet to be approved and outline why Heathrow, on the western edge of London, is the preferred option.

"By backing the northwest runway at Heathrow airport and publishing our proposals, we are sending a clear signal that when we leave the EU, we are open for business," Transport Secretary Chris Grayling will say, according to advance extracts of his speech.

To assuage critics, the transport department said that compensation worth up to 2.6 billion pounds will be made available to those affected, and that development consent will only be granted "if the new runway can be delivered within existing air quality limits and climate change obligations".

The policy statement will also be scrutinised by lawmakers, ahead of a vote on the new runway, which is expected in late 2017 or early 2018.

(Reporting by Alistair Smout; editing by Stephen Addison)