Global grain giant Bunge will merge with Glencore-backed Viterra, in a deal that will create one of the world's largest agribusinesses. 

The $34 billion deal was unanimously agreed to by board members from both companies and Bunge's chief executive Greg Heckman will lead the combined entity, according to detail's released by Bunge late on Tuesday night.

Both companies operate in the already highly concentrated global grain market, so the deal is likely to come under close scrutiny from competition regulators.

In Australia, the US-headquartered Bunge owns an export terminal at the Port of Bunbury, opened in 2014, as well as two grain receival sites in Western Australia, while the company's local head office is based in Melbourne.

It is part of ABCD group of companies — including Archer Daniels Midland, Bunge, Cargill and Louis Dreyfus — which collectively control between 75 and 90 per cent of the global grain trade, according to estimates, as well trading in coffee, sugar, cocoa, oilseeds and biofuels, among other commodities.

Dominant in South Australia 

Viterra is the dominant grain handler in South Australia, with 55 receival sites in SA and western Victoria, and six port terminals at Port Adelaide's Outer Harbour and Inner Harbour, Port Giles, Thevanard, Port Lincoln and Wallaroo.

Canadian-based Viterra bought ABB Grains in 2009, which at the time was one of Australia's largest agribusinesses.

In 2012 the Swiss-based global commodities giant Glencore bought a 49.99 per cent staked in Viterra, rebranding its Glencore Agriculture brand to Viterra.

Its other owners are the Canada Pension Plan Investment Board and British Columbia Investment Management Corporation.

The merger would bring Bunge's revenue, which was $US67.2 billion in 2022, Reuters reports.

In 2017, Viterra publicly expressed interest in acquiring Bunge to expand its agricultural interests.

Both Bunge and Viterra are significant buyers of Australian grain, by volume, according to online trading platform Clear Grain Exchange.

Local scrutiny likely

The Australian Competition and Consumer Commission will scrutinise the local impact of the merger, and has the power to oppose it and mandate divestments.

The last decade has seen a number of major global agribusiness mergers and acquisitions, including ChemChina's takeover of Syngenta, Bayer's acquisition of Monsanto and Nutrien's purchase of Landmark and RuralCo.

While the physical assets owned by Bunge and Viterra are located in two separate states, they do compete to buy and sell Australian farmers' grain all over the country's wheatbelts.