This has been emphasised by the hotly contended battle for the listed GPT Metro Office Fund by Growthpoint Properties, which has now crossed the 50.1 per cent threshold and declared the offer unconditional.

Once completed it will increase Growthpoint's presence in the suburban office market by a further six, high-quality office towers in Sydney, Melbourne and Brisbane.

Growthpoint reported a strong full-year net profit of $224.2 million, which was down 20.8 per cent but included a range of one-off property valuations.

The more accurate distributable income was 21.9¢ per security, which was a 3.3 per cent gain on the 2016 year, and the annual distribution was 20.5¢ per security, payable on August 31.

Growthpoint chief executive Tim  Collyer said the group had enjoyed office leasing success, namely the lease to Country Road/David Jones for new headquarters over 23,000 square metres at Buildings 1 and 2, 572 Swan Street, Richmond, Melbourne, for an average lease term of 14.5 years.

The rival bidder for the GPT Metro Fund, Centuria Capital, which still has a 16 per cent stake in the fund, has also focused on the metropolitan markets and also unveiled solid results for the year of $10.4 million in net profit, a rise of 65 per cent. It was at the upper end of guidance provided to the market in December and the 2016 fully franked dividend was 5.25¢ per share.

John McBain, Centuria's chief executive said funds under management increased 21 per cent from $1.6 billion to $1.9 billion and unlisted property fund acquisitions totalled $265 million. The listed Centuria Metropolitan REIT portfolio book increased 9.3 per cent to $400 million with distributions on forecast.

Mr McBain said during the past year the group has boosted its suburban office portfolio with the acquisitions of interest in the Australian Technology Park for $104 million, a 50 per cent interest in 203 Pacific Highway, St Leonards, for $43 million and a 50 per cent interest in 8 Central Avenue, Redfern, for $109 million and the acquisition of The Zenith complex at Chatswood for $280 million.

According to Savills, Sydney's fringe office markets have recorded their strongest vacancy rates in more than a decade as the nation's key capital city markets continue their climb out of double-digit vacancy and inflated incentives.

The falling vacancy is driving growth in net effective rents and with the NSW government's announcement of registered projects totalling $390 million in Parramatta and Winten Property Group's acquisition of a development site at 1 Denison St, North Sydney, developers are taking notice.

According to Savills senior analyst research & consultancy Houssam Yakzan​, average prime net face rents have increased by around 8 per cent in north shore markets and 7 per cent in Parramatta, with corresponding falls in incentives.

The combined north shore vacancy, including North Sydney, Crows Nest/St Leonards, Chatswood and Macquarie Park-North Ryde stands at 7.2 per cent, the lowest since the 5.3 per cent figure recorded in 2001.

Savills director office leasing, Simon Van Grootel​, said while there was no doubt the Sydney non-CBD office markets had picked up over the past 12 to 18 months, withdrawals for the compulsory metro rail acquisitions, residential and hotel conversion, and the lack of new supply, were key contributors to the lower vacancy rates.

"That has seen rental growth and incentives decline and those factors along with continued withdrawals and continued falls in vacancy are going to drive new construction but in the current market, that is likely to require pre-commitment," Mr Van Grootel said.