Top executives for 21st Century Fox Inc and News Corp wanted a headquarters that would embrace the latest concepts in collaborative offices.

A new office tower was not the first choice, said architect Bjarke Ingels.

Before working with him to build what would be New York's third-tallest skyscraper at the World Trade Center, the media companies explored converting an existing building, he said.

Mr James Murdoch, Fox's co-chief operating officer and the person spearheading the headquarters initiative, favoured the wide floors and open design pioneered by technology firms and not often found in soaring towers, said Mr Ingels.

"He was quite certain he didn't want to build a big skyscraper," added Mr Ingels, 40, at his lower Manhattan studio, sitting in front of a model of 2 World Trade Center and the surrounding site.

It was the concept of interactivity in design in 2 World Trade Center that helped lead Mr Murdoch to embrace the new tower, said Mr Ingels. The architect incorporated some of what Mr Murdoch liked in the Starrett Lehigh Building, a former freight terminal in Chelsea, where Mr Ingels' own studio was located at the time.

"He wanted a more raw creative work environment," said Mr Ingels, who is also working on Google Inc's Googleplex campus in Silicon Valley. "He wanted to break down the vertical segregation that comes from being a multi-storey tenant."

Fox and News Corp signed a letter of intent two weeks ago to be the anchor tenants at 2 World Trade Center, with Mr Ingels taking over the design from Mr Norman Foster, in a deal that would pave the way for developer Larry Silverstein to build the last of the four towers at the lower Manhattan site.

Mr Nathaniel Brown, a spokesman for Fox, declined to comment on the headquarters process.

In a memo to employees last week, the companies said the building "would facilitate idea sharing, connectivity and collaboration among colleagues and departments".

The bottom of the building, the biggest of seven sections that will climb ziggurat-style to about 408m, will support Fox's broadcast operations, including television studios, Mr Ingels said. The floors would be about 56,000 sq ft, about the size of a football field.

The concept of floors in the tower, however, is a bit inexact. The design features wide stairs between different levels, so people will be encouraged to move around and interact with others in different work groups, said Mr Ingels.

His renderings include what appears to be the main Fox News newsroom, before a ground-floor window that looks out at the arches of architect Santiago Calatrava's trade centre transit hub. Another of Fox's studios would take advantage of the views the tower will offer of the East River.

News Corp would be in the third section, which would include the Wall Street Journal and New York Post newspapers.

Each section is to be 12 to 15 storeys, according to Ms Daria Pahhota, a spokesman for the architect's Bjarke Ingels Group firm.

Fox and News Corp, which split in 2013, would have executive offices in the fourth section, somewhere between 36 and 48 storeys above the street. The rest of the 2.8 million sq ft tower would be Silverstein's to lease to other tenants, except possibly for what Mr Ingels called a "fantasy" idea for "an epic screening room" on the upper floors, where Fox-produced films will compete with views of the city for oohs and ahhs.

If all goes to plan, the 2 World Trade tower would be built at the corner of Church and Vesey streets.

Bloomberg