Kiwi Property is reporting a net increase of $57 million in the value of its portfolio of shopping centres and office buildings for the year to March.

That's lifted the overall value of the portfolio to $2.28 billion.

Among its shopping centres are Sylvia Park and LynnMall in Auckland.

Kiwi Property Chief Executive Chris Gudgeon says the portfolio has benefited from high occupancy rates, stronger retail sales at key assets and strong interest from offshore investors in New Zealand property.