Despite the rising costs, Singapore remains competitive against Tokyo and Hong Kong, he said.
But he said there is concern that the "tightening availability of space is starting to impact businesses' ability to accommodate growth."
The consultancy said developing countries accounted for half of the 20 markets with the fastest growing occupancy costs for prime office space.
Tokyo's inner central area fetched 145.
68 US dollars per square foot per annum, coming after global leader London's West End, real estate consultancy CB Richard Ellis said in its six-monthly report.
It measured office occupancy costs which cover rentals, taxes and service charges.
London city was the third most expensive district worldwide, with Tokyo's outer central district following at fourth place.
Hong Kong was number five globally and Mumbai seventh behind Moscow but ahead of eight-ranked Paris.
Office occupancy costs in Mumbai's Nariman Point surged more than 158 percent to 106 dollars p