PARIS, Nov 15 (Reuters) - InVivo will open a marketing office in Saudi Arabia early next year as it seeks to secure new outlets at a time of changing global grain demand, the French agribusiness group's chief executive told Reuters.

The office, to be based in the Saudi port of Damman, aims to secure grain supplies for local feed makers in the fast-developing country, InVivo CEO Thierry Blandinieres said.

The cooperative group, with activities from grain trading to wine distribution, became one of Europe's largest agricultural firms through its takeover of French rival Soufflet in 2021.

Algeria has been traditionally the biggest market for French wheat but exports to the north African country have fallen dramatically as Algiers turned to cheaper Russian supplies.

French wheat exports to Algeria this season were down 85% by the end of last month compared to a year earlier. However, the fall was set to be compensated later in the season by a sharp rise in sales to China, where crops have been damaged by rain.

"Geographies are changing in terms of customers. We know that Algeria is no longer a loyal customer. The good surprise is that the Chinese order a lot, that Egypt is buying again and Saudi Arabia wants to have ties with France," Blandinieres said.

"But China will eventually stop, it is not a continuum, so we have to find outlets elsewhere and that's what we are trying to do," he said, adding that InVivo was also working on securing its west African markets.

The Saudi office will be directed from Dubai by Aman Sethi, who was previously based at InVivo's Singapore office, Jean-Francois Lepy, head of InVivo's trading arm Soufflet Negoce, said separately.

InVivo said on Wednesday its Malteries Soufflet unit had completed the takeover of Australia's United Malt Group following clearance from relevant regulatory authorities and shareholders, creating the world's largest maltster. ($1 = 1.5370 Australian dollars) (Reporting by Sybille de La Hamaide; Editing by Alexander Smith)