Global online travel company Expedia will move its new Australian headquarters to Martin Place after its takeover of local competitor Wotif last year.

The group has landed on Charter Hall's landmark tower at 1 Martin Place, which is attached to the Westin Hotel, and will take three floors, or about 4500 square metres. It is understood a formal lease agreement will be signed within the next week.

The building, which was facing a tenant exodus several years ago, is now a leasing success story. Expedia's arrival will mean the building is more or less full.

The deal highlights how Martin Place, the city's traditional heart of commerce, has reinvented itself. Once the domain of traditional banks and law firms, the precinct has become the target of rapidly expanding and new technology companies such as LinkedIn, Dropbox, WeWork and Apple that want a top location. 

Charter Hall's 1 Martin Place is a prime example. Many had predicted the building would struggle with vacancy when Macquarie Group, like many traditional corporations in Martin Place, revealed intentions to move its headquarters.

However, the bank surprised the market by retaining more tower space than initially expected (12,000 square metres).

Global networking website LinkedIn also agreed to move its Australian headquarters to 1 Martin Place last year, more than doubling in size to about 4000 square metres. The Australian Prudential Regulation Authority also opted to move in.

Sources suggested Expedia's net rent would be about $800 a square metre.

Charter Hall Group declined to respond to a request for comment. CBRE Global Workplace Solutions, who acted on behalf of Expedia, also declined to comment.

Expedia took over Wotif in November last year in a $703 million deal to boost its presence in Australia. Before the takeover, Wotif employed 620 staff with about 170 technology workers in Sydney. It is understood the deal includes Expedia's corporate travel arm, Egencia.

At present, Wotif is in Atlassian's former offices at the Corn Exchange Building at 173-185 Sussex Street. It signed a five-year lease in 2013 and was understood to be planning to sublease the space. Expedia is based at 77 King Street.

Sources said the company planned to move to its Martin Place offices in early 2016.

The IT sector is a fast-growing part of Sydney's office market. Many of these new companies now want to be located in premium grade buildings. E-commerce giant Amazon and social media company Twitter for example expanded significantly this year at the Citigroup Centre on Park Street.

At Martin Place, Apple will move to the Pembroke-owned 20 Martin Place building next year while Dropbox and WeWork have signed deals to move to 5 Martin Place.