Downer Group

Downer's foundations were laid in the 19th century, when Walkers Limited and Clyde Engineering were founded in Australia, and the Public Works Department and Electrical Telegraph Department were founded in New Zealand. They merged in the 20th century to form parts of the Downer Group. The 20th century also saw the purchase of companies that now make up Downer's core divisions: railway manufacturer Evans Deakin & Company (EDI) and mining contractor Roche Brothers.

In 1933, the Downer Group was founded in New Zealand by Arnold Downer, as Downer & Co, focusing on providing engineering and construction services to the public and private infrastructure sectors in New Zealand, including the New Zealand Public Works Department. In 1954, Downer & Co merged with William Cable Holdings and, in 1964, with A&G Price, to form Cable Price Downer.

In 1994, Downer merged with Hong Kong-based Paul YITC. In 1996, the company purchased Works Corporation, the state-owned enterprise civil construction arm of the New Zealand Ministry of Works & Development. In 1997, mining contractor Roche Brothers was acquired. In 1998, Downer purchased major roads contractor Technic Group, and was first listed on the Australian Securities Exchange.

In 2000, road-sealing business Bitumix was acquired from BP. In 2001, Downer merged with Evans Deakin Industries to form Downer EDI. Between 2003 and 2008, Downer also acquired Stork, QCC, Snowden, Emoleum and Excell Corporation. In October 2014, the construction assets of Tenix were acquired.

In March 2017, Downer acquired Hawkins, one of New Zealand's largest builders, and in June 2017, took majority ownership of Spotless Group Holdings through a hostile takeover. It took full ownership of Spotless for $1.27 billion in October 2020. The Spotless acquisition was the largest in Downer's history.

Downer reports its financial results under five service lines: Transport; Utilities; Facilities; Engineering, Construction and Maintenance (EC&M); and Mining.

Rail/Bus

Downer Rail was formed in March 2001 as EDI Rail following the purchase of Evans Deakin Industries by Downer Group. Evans Deakin operated the former Clyde Engineering plants at Kelso and Somerton and Walkers Limited, Maryborough plant. It reopened the former Cardiff Locomotive Workshops to build CityRail M sets. In July 2007 it was renamed Downer Rail.

In 2008 Locomotive Demand Power was established as a subsidiary to lease locomotives. In November 2009 Downer Rail became a tram operator through its 49% shareholding in Keolis Downer that operated the Yarra Trams franchise in Melbourne. In July 2014, Keolis Downer commenced operating the G:link light rail line on the Gold Coast.

In March 2015, Keolis Downer purchased bus operator Australian Transit Enterprises which operates the Hornibrook Bus Lines, LinkSA, Path Transit and SouthLink operations with 930 buses. In July 2017, Keolis Downer commenced operating bus and ferry services in Newcastle under the Newcastle Transport brand.