ASX 100 Top Companies List by Market Cap as on Jan 1st, 2020

BHP Billiton is Metals, Mining, Petroeum Company with headquarters in Australia. BHP Billiton is trading in London Stock Exchange and Australia Stock Exchange. BHP Group has 80,000 employees as on June 2020.

RIO TINTO GROUP is UK and Australia based Metals and Mining Company. Company producing major products are aluminum, copper, diamonds, gold, industrial minerals (borates, titanium dioxide and salt), iron ore, and uranium. Rio Tinto had around 47,100 employees around 35 countries as on 2019.

They are strongly represented in Australia and North America, and also have significant businesses in Asia, Europe, Africa and South America.

COMMONWEALTH BANK is Australia based bank and it is largest bank in Australia. Around 43,585 employees working for Common Wealth Bank as on 2020. 

CSL Limited is BioTechnology company headquartered in Melbourne, Australia. CSL Limited has around 25,000 employees as on 2019. CSL has acquired a number of companies. They include: Aventis Behring, which is now known as global biotech leader CSL Behring, U.S. plasma collector Nabi, which helped to form the world's premier plasma collection company in CSL Plasma, the Novartis influenza vaccine business, now integrated and known as Seqirus, the world's second largest influenza vaccines company and Calimmune, a leader in gene-modification and cell delivery technology.

WESTPAC BANKING CORPORATION is Australia based Banking and Financial Services Company.  Westpac Bank offers services in Australia and New Zealand. Westpac provides a broad range of consumer, business and institutional banking and wealth management services through a portfolio of financial services brands and businesses. They have over 33,288 employees as on 2019. Headquarters is in Australia.

National Australia Bank commonly called NAB is Australia Bank and headquartered in Melbourne, Australia. By market capitalization, NAB is fourth largest bank in Australia followed by Common Wealth Bank, Westpac Bank and ANZ. Bank of New Zealand is subsidiary to NAB. They had over 33,950 employees over 900 locations as on 2019.

ANZ Bank is third largest bank in Australia and its headquarters in Melbourne, Australia. As on 2019, ANZ Bank had 39,060 employees.

Macquarie Group Limited is a  Investment Bank and Financial Service Oriented Company with headquarteres in Sydney, Australia. Macquarie Group provides banking, advisory, trading, asset management and retail financial services across the globe. As on 2018, they have employees around 14500. 

Macquarie is a diversified financial group providing clients with asset management and finance, banking, advisory and risk and capital solutions across debt, equity and commodities.

Headquarters in Perth, Australia. It has diverse business operations cover: supermarkets, liquor, hotels and convenience stores; home improvement; office supplies; department stores; and an industrials division with businesses in chemicals, energy and fertilisers, industrial and safety products and coal.

WOOLWORTHS GROUP LIMITED is Australia's biggest Super Markets company. Woolworths Super Markets are spread across the Australia. As on 2018, Woolworths group had around 205,000 employees.