Lowy Family Group has sold its seven per cent stake in Westfield Retail Trust for $663.7 million.

The sale was made as part of a broader investment strategy to diversify its investments internationally, a spokesman for Lowy Family Group said in a statement.

The statement, issued to the Australian Securities Exchange, said the selling price was $3.09 per security.

This compares with a closing price, down one cent at $3.18 on Thursday.

The trust's principal investment is the joint-venture ownership with the Westfield Group in a portfolio of 47 major shopping centres mostly in Australia and some in New Zealand.

The statement said that, as the largest shareholder in the Westfield Group, the Lowy family's interest and continuing commitment to that group remained unchanged.

Westfield Group, which manages 150 shopping centres in five countries, reported on Wednesday that it lifted its net profit to $1.72 billion profit in the year to December 31, from $1.532 billion in 2011.

Westfield Group was up six cents at $11.20.