LONDON (AP) — Britain can be a bastion of stability in uncertain economic times, and can balance economic growth with environmental protection, Prime Minister Gordon Brown said in excerpts of a speech to be given today.

Brown gave the UK government's backing for construction of a third runway at London's congested Heathrow airport — a plan fiercely opposed by environmentalists — while repeating a commitment to cut emissions of the greenhouse gases blamed for climate change by 60 percent by 2050.

"We know ... that even as we place strict environmental limits on noise and air pollution and ensuring aviation pays its carbon costs, we have to increase capacity at our airports, particularly Heathrow," Brown said in extracts from the speech released in advance by his office.

"Our prosperity depends on it: Britain as a world financial centre must be readily accessible from around the world."

Brown's speech to the Confederation of British Industry, an employers' group, also contained a proposal to simplify planning procedures for major infrastructure projects such as the long-awaited east-west Crossrail train line across London.

He said a decision on whether to build a new generation of nuclear power stations would be announced in the new year. The government has said that in principle it favours replacing Britain's ageing nuclear plants.

Brown was Britain's Treasury chief for a decade before taking over as prime minister in June, and the stability of the economy over that period is one of his strongest boasts.