CIMIC Group Limited (formerly Leighton Holdings) is an engineering-led construction, mining, services and public private partnerships leader working across the lifecycle of assets, infrastructure and resources projects.

Founded in 1949 by Stanley Leighton, Leighton Holdings was first listed on the Melbourne Stock Exchange in 1962.^[2] The company formed Leighton Asia, based in Hong Kong, in 1975.^[3]

In July 1983 Leighton Holdings, purchased Thiess Contractors, with its major shareholder, Hochtief, becoming a shareholder in Leighton Holdings.^[4][5][6] In April 1997, the Welded Mesh structural materials division was sold to Smorgon Steel.^[7]

In 2000, Leighton Holdings bought a 70% stake in John Holland; this was increased to 99% in 2004 and 100% in December 2007.^[8] Hochtief became a majority shareholder of Leighton Holdings in February 2001.^[9]

In October 2013, Fairfax Media alleged that Leighton Holdings had made corrupt payments to Hussain al-Shahristani, Deputy Prime Minister of Iraq, to secure an oil pipeline contract in Iraq and other contracts.^[10] Basil Al Jarah, the Iraq country manager for Unaoil, a Monaco-based company allegedly acting for Leighton Holdings, subsequently pleaded guilty to corruption.^[11]

By March 2014, Spanish company ACS Group, through its acquisition of a majority shareholding in Hochtief, was the majority owner of Leighton Holdings.^[12] In June 2014, Verdes also became chairman of Leighton's executive board.^[13]

In December 2014, Leighton Holdings sold John Holland to China Communications Construction for $1.15 billion.^[14]

In April 2015, Leighton changed its name to CIMIC Group (abbreviated from Construction, Infrastructure, Mining and Concessions).^[15]

In March 2016, CIMIC purchased mining company Sedgman for A$256 million.^[16] In December 2016, CIMIC purchased engineering company UGL Limited for A$524 million.^[17]

In November 2021, the Ventia services division was spun off with CIMIC retaining a 33% shareholding.^[18]

In March 2022, CIMIC was accused of arranging its affairs through the sale of its Middle Eastern business interests to avoid paying workers, subcontractors and suppliers in the region. Fatima Almass Al-Hamad, a judicial guard in Qatar, who was appointed by the court as an administrator of the Qatar business, Leighton Contractors Qatar, described the situation as "a humanitarian disaster".^[19]

In April 2022, Hochtief increased its shareholding and commenced action to compulsorily acquire the remaining shares.^[20]

In 2022, CIMIC was delisted from the Australian Securities Exchange.^[21]

CIMIC Group includes the following businesses:^[22]

• CPB Contractors (construction)
• Leighton Asia (construction)
• Broad Construction (construction)
• Thiess (joint control) (mining)
• Sedgman (mining)
• UGL Limited (services)
  • UGL Rail
• Pacific Partnerships (development and investment)
• EIC Activities (engineering consultancy)