The maker of Marlboro cigarettes, Altria Group, says it will sell more than $2.2bn (£1.7bn) of shares in AB InBev, the owner of the Bud Light and Stella Artois beer brands.
The move will see Altria offloading 35 million AB InBev shares.
The tobacco giant currently owns a stake of around 10% in the world's biggest brewer, worth about $12.7bn.
Bud Light sales have been hit after a US boycott over its work with transgender influencer Dylan Mulvaney.
The sale is "an opportunistic transaction that realises a portion of the substantial return on our long-term investment," Altria's chief executive, Billy Gifford, said in a statement.
"Our continued investment reflects ongoing confidence in ABI's long-term strategies, premium global brands and experienced management team," he added.
Belgium-based AB InBev also said in a filing with regulators that it had agreed to buy $200m of its shares from Altria.
In February, the company - which also owns a stable of other major beer brands including Beck's, Corona and Leffe - said its annual revenues in the US fell by 9.5% "primarily due to the volume decline of Bud Light."
However, globally AB InBev saw total revenues rise by 7.8% for the year, which helped to boost 2023 profits to more than $6.1bn.
Bud Light faced a wave of criticism after it sent a personalised can of beer to Ms Mulvaney for an online post.
Within weeks, industry analysts reported that Modelo - sold in the US by a rival firm - had replaced Bud Light as the top-selling beer in the US, and rivals such as Coors Light and Miller Light were gaining fast.
Following Ms Mulvaney's social media post promoting the beer with her personalised can, many on the right criticised the company for going "woke".
Woke is an informal term from the US, meaning alert to injustice and discrimination in society, particularly racism and sexism. It is often used by the right in a derogatory way towards left-leaning views on topics from climate change to support for minorities.
Musician Kid Rock, NFL player Trae Waynes and model Bri Teresi all shared videos of themselves shooting Bud Light cans.
The company's response to the criticism - which included putting two executives blamed for the relationship on leave - was subsequently decried by many on the left.
AB InBev's US-listed shares fell by almost 4% in extended trading in New York.
Source: BBC
