Mr Mars, who joined MLA in 2009, will take up a senior position at the head office of the giant international meat processor in Brazil.

MLA chairman Rob Anderson said Mr Mars' pending departure would have little impact on the make-up of the MLA board.

"At this stage, it is not known when Mr Mars will cease in his JBS CEO role, or what his next role within JBS might be or where it may be located," he said.

"The MLA board will remain in discussions with Mr Mars as his future employment situation develops and will review its position in line with the MLA constitution should circumstances require."

Mr Mars' replacement is 42-year-old Andr Nogueira, a former head of corporate banking for the Bank of Brazil in its New York and Sao Paulo offices before he joined JBS-USA as chief financial officer.

Mr Nogueira will arrive at his new post as meat processors wrangle over the merits of passing through price increases to consumers or cut costs from their operations as they battle ever tightening margins with a persistently high Australian dollar and historically highly-priced cattle placing massive pressure on the bottom line.

Mr Mars said he had thoroughly enjoyed his time working in the "great country of Australia".

"It's a place in which I have always dreamed about working. For me, the real challenge is in building new businesses and - while I have greatly enjoyed growing and shaping the JBS operations in Australia - I believe there is now an opportunity for someone else to develop the business in its next stage," he said.

With 28 years' experience in the meat industry, Mr Mars was responsible for the management of JBS Australia's extensive meat processing facilities and feedlot operations across Australia, while overseeing massive growth of the company's Australian holdings during his four-year tenure.

While specific detail of his new role has not been announced, Mr Mars's appointment comes as the meat sector globally witnesses accelerated merger and acquisition activity, particularly in Europe and the US.

The ongoing debt crisis in Europe is forcing more cash-strapped beef companies under credit strain to consider the consolidation path, an environment well suited to Mr Mars' specialist skills in business expansion.