AMP Capital has submitted its second development application for its Quay Quarter headquarters covering seven separate properties, including 33 Alfred Street, 50 Bridge Street and a number of properties on Young and Loftus streets, equivalent to 1.1 hectares of property.

The redevelopment at the northern end of the city will throw down the gauntlet to its western corridor rival, Barangaroo.

According to the latest Rider Levett Bucknall Crane Index, there are more than 125 cranes within the Sydney region, and within five kilometres of the Sydney GPO there are 60 cranes dominating the skyline.

These include Barangaroo South, where Tower 2 has been adorned with the St George Bank and BT signs at the top, to Haymarket in the south, incorporating the new International Convention Centre, being developed by Lend Lease.

The new 49-storey building, in a "twisting style", will allow natural light into every floor and double the floor space to accommodate an open-plan style office.

It is being designed by the Danish architects 3XN, and at the base of the tower is an urban green space available for office workers and the general public to enjoy views of the Harbour Bridge. This garden forms the roof for the two-level retail building below.

3XN founding partner and creative director Kim Herforth Nielsen said the commercial office tower at 50 Bridge Street is designed as a 'vertical village' that takes on board the ambience and social character of the street.

"It also reflects and maintains the connection to the nearby and world-renowned Botanic Gardens and Macquarie Place Park, with an emphasis on green space within the building," he said.

AMP Capital managing director office and industrial Louise Mason said the landmark Quay Quarter Sydney project was a "further demonstration of AMP Capital's long-term commitment to Circular Quay", where it built Australia's first skyscraper and where the company has been located for more than 50 years.

The tower at 50 Bridge Street is jointly owned by investors in the AMP Capital Diversified Property Fund and the AMP Capital Wholesale Office Fund.

Construction is earmarked to start in 2017 once the necessary approvals are secured and is expected to take about 2½ years to complete the construction.

Revitalising the Circular Quay area will also involve the conversion of the former Coca-Cola Amatil building, near the Cahill Expressway, and the Gold Fields House office building into apartments and a proposed hotel.

At the opposite end of the quay, Lend Lease has also submitted plans for a new 220-metre office tower on Alfred-Pitt-Dalley-George streets, known as the APDG block. It is looking to sell the site, but retain the development, with the super fund, Cbus Property, said to be the front-running buyer.