India's financial capital Mumbai ranks second only to global commercial hub London in terms of office rentals, while the national capital is not far behind at eighth spot.

The cost of a square feet at Mumbai's Nariman Point has risen 55 per cent over last year to $189.51 (occupation cost in US $/sq ft/annum).

However, it is a distant second to London's West End, which topped the list with $328.91, according to a recent survey by global realty consultant CB Richard Ellis.

According to CBRE Research's semi-annual Global Market Rents survey, which tracks the world's most expensive markets as well as markets with the fastest growing rents over the past 12 months, Delhi ranks eighth in the most expensive office markets of the world (with rental of $126.73).

"London's West End, Mumbai, the City of London and Moscow are the top four most expensive office markets in the world," CBRE said in a statement.

In the category of fastest growing office rents, Mumbai ranked third with 55 per cent jump in last 12 months, as Singapore led the list with occupancy cost rising by 83 per cent during the past year.

Bangalore stood at sixth place with 49 per cent jump, while New Delhi is at 12th position with 34.3 per cent rise in office rental in the last one year.

"This is reflective, on the one hand, of the great performance of the economy, but on the other hand, of acute shortage of prime office space in Mumbai," CBRE South Asia chairman and managing director Anshuman Magazine said.

Such high cost of office space in the financial capital of an emerging country like India could be a deterrent for investments, he added.

The report surveyed office occupation costs in 171 cities worldwide. Delhi and Mumbai were the only two Indian cities among the 50 most expensive office markets. Software hub Bangalore also found a place in the list of top 50 markets with fastest growing rentals.

The CBRE report follows that of another global real estate consultant Cushman & Wakefield, which had recently put Khan Market in New Delhi as the most expensive retail destination in the country with rentals of Rs 950 per sq ft per month in the second quarter this year.

It witnessed an annual growth of 35.7 per cent over the same period last year.