Mumbai has lost its sheen of being in the top 10 most expensive office locations in the world for the first time in six years and slipped to the 15th position in the new list compiled by global realty consultant Cushman & Wakefield.

"Mumbai's Nariman Point drops to 15th most expensive central business district (CBD) office location from its previous 8th position... This is also the first time in over six years that Mumbai fell out of the top 10 rent rankings," Cushman & Wakefield (C&W) said in a statement.

As of December 2011, the occupancy cost in Mumbai's CBD stood at USD 73.3 per sq ft, registering a decline of 8 per cent it added.

"The decline of Mumbai's CBD rentals is reflective of two very important aspects -- firstly, that other micro markets across Mumbai are witnessing a growth vis-a-vis the CBD.

"Secondly, that there is a certain amount of rationalisation in rentals in locations that had seen unprecedented rise in peak periods of 2007-08," C&W Executive Director Ravi Ahuja said.

Nariman Point has seen a steady and planned decline in the last few years as other micro markets like Bandra-Kurla Complex (BKC) and Lower Parel recorded a corresponding rise, he added.

"BKC was consciously planned to decongest the CBD over a period of time and we see this phenomenon setting in," Ahuja said.

According to the study by C&W, Hong Kong, London and Tokyo remained firm in the top three positions with rentals of USD 244, USD 239 and USD 197 per sq ft in each year, respectively.

The new entrants in the 2012 list are Beijing and Sydney. While Beijing is at the 5th position with an annual rental of USD 130 for every sq ft, Sydney was at the 7th place with an occupancy cost of USD 119 for a sq ft a year, C&W said.

Commenting on the scenario in India, Ahuja said, "The trend of shift in focus from the CBD to other locations is also visible in the prime office markets in NCR and Bangalore, where suburban and peripheral locations are witnessing a rise in activities."

These markets have cost advantages over traditional locations and offer greater value in terms of social and civic infrastructure, besides a good talent pool from the vicinity, he added.

"Thus we are likely to see this phenomenon continue for another few quarters," Ahuja said.