Australia's competition regulator has raised concerns over an $11 billion deal by Anheuser-Busch InBev to sell its local operations to Japan's Asahi Group Holdings Ltd., dealing a blow to the world's largest brewer's efforts to cut debt.

The Belgium-based brewer, weighed down with some $100 billion net debt after its 2016 acquisition of rival SABMiller, has been selling assets and took its Asian business public this year to reduce debt and focus on other fast-growing markets.

It had hoped to close the sale of Carlton & United Breweries (CUB) to Asahi in the first quarter of 2020 and use the bulk of the proceeds to cut debt.