Office markets around the world are increasingly reporting an upturn in demand, with investors hoping to take advantage of improving economic situations and rising rental and occupancy rates.

In Asia the sector has enjoyed a sharp bounce back in values over the past year, with rents in Hong Kong rising by 51 per cent in 2010, Cushman & Wakefield's Office Space Across the World report shows.

Added to this, Brazil has also seen an increase in investor interest, with Rio de Janeiro becoming the first South American location to knock New York off the top spot in the Americas region.

In fact, South America showed the strongest regional rental performance last year, with growth of 12 per cent. This is in contrast to North American markets which experienced stable rents at best, the report added.

Brazil saw a rental rise of over 25 per cent and accounted for two of the three most expensive locations within the Americas region.