WeWork has sent a shockwave through the office real estate sector globally with its model of taking on long-term leases and renting them out to corporate clients on a flexible short-term basis.

Its funky, Silicon Valley style co-working environment have proved a hit, transforming it into a major player in the space of a couple of years.

The model, however, has raised skepticism among investors, who are concerned that WeWork could be left holding substantial liabilities in a downturn as clients evaporate.

Flexible office providers have dominated leasing in major gateway cities, most notably London, New York and San Francisco, a sign of growing demand by companies and not just the start-ups and entrepreneurs that put coworking on the map.

Below is a comparison on some of the top office space providers in the market and how they compare on some key metrics:

- WeWork (as of June 30)

Total liabilities: $24.6 billion

Total square feet: Did not report square footage it manages

Footprint: 528 locations in 111 cities across 29 countries

Revenue: $1.54 billion (first half of 2019)

- Boston Properties Inc (as of June 30):

Total liabilities: $13.25 billion

Total square feet: 50.9 million

Total properties: 193

Footprint: United States

Market Cap: $19.67 billion

Revenue: $733.7 million

- British Land Company Plc (as of March 31 - for H1, 2019):

Total liabilities: 3.57 billion pounds ($4.30 billion)

Total square feet: 22 million

Total properties: 127

Footprint: United Kingdom

Market Cap: 4.41 billion pounds

Revenue: 904 million pounds

- IWG Plc (as of June 30 - for H1, 2019):

Total liabilities: 298.1 million pounds

Total square feet: 50 million

Total properties: More than 300

Revenue: 1.30 billion pounds ($1.57 billion)

Footprint: 18 countries

Market Cap: 3.72 billion pounds

Cash-in-hand: 385.1 million pounds (Cash flow before net growth capital expenditure, share repurchases & dividend)

- Mitsubishi Estate Co Ltd (as of Aug. 6)

Total liabilities: 77.26 billion yen ($730.04 million)

Total square: Not available

Total properties: Not available

Revenue: 265.88 billion yen

Cash-in-hand: 243.34 billion yen (at the end of the year)

Footprint: Japan, U.S., U.K., China, Singapore

(Reporting by C Nivedita, Vibhuti Sharma and Soundarya Jayaraman in Bengaluru; Editing by Arun Koyyur)