Westfield Group will pay $US800 million to take full ownership of a shopping centre being constructed at New York’s World Trade Centre.

The shopping centre giant will buy the Port Authority of New York’s 50 per cent stake in the World Trade Centre retail premises, taking its total investment in the site to $US1.4 billion.

Westfield and the Port Authority entered into a joint venture to own and operate the retail space at the under-construction World Trade Centre in 2012.

But the Port Authority on Thursday said it had sold its stake to Westfield to allow it to “refocus agency resources on our core transportation mission.”

The retail premises are scheduled to open in 2015.

AAP