In 2015, Post bought Minnesota-based MOM Brands, known for its bagged Malt-O-Meal cereals, and merged that company with its existing Post cereals.
Bright Food is the parent firm of a number of listed companies including Bright Dairy and Food.
Bright agreed to buy a 60% stake in Weetabix in 2012 from private equity firm Lion Capital in a deal that valued it at 1.2 billion pounds.
Turrell said at the time Weetabix doubled its business to China a year ago, and there was a growing demand for high quality, imported British foods. The deal signals Bright Food's struggle to appeal to Chinese consumers, who prefer hot rice meals over the United Kingdom staple.
This morning, it sold the brand - along with Alpen muesli, Ready Brek, Barbara's and Weetos - to St. Louis-based Post Holdings for $1.8 billion.
Post Holdings' portfolio includes Honey Bunches of Oats, Pebbles, Great Grains, Pos Shredded Wheat, Post Raisin Bran, Grape-Nuts and Honeycomb.
He also confirmed that Post will seek to make a £20m annual cost saving through "procurement synergies", but would not alter the size or shape of the Weetabix biscuits.
George Salmon, Equity Analyst at Hargreaves Lansdown, said: 'The deal comes hot on the heels of Kraft Heinz's bid for Unilever and 21st Century Fox's approach for Sky, and further transatlantic deals may be flushed out by the strong dollar and rising United States interest rates.
"This is a part of our internationalization strategy. Going forward Bright will stick to our overseas push", according to Bright spokesman Pan Jianjun.
However, according to a Weetabix spokesperson, the company's market share for cereals and drinks rose from 15.3% to 16.4% in the United Kingdom past year.
The CEO of Post Holdings, Rob Vitale, has said that he is "excited about the growth opportunities" that the company's acquisition of Weetabix provides. It said it wanted to grow the Weetabix brand in China and overseas and floated the idea of listing the cereal maker in 2014, but it never gained enough traction in penetrating the Chinese market where consumers traditionally eat hot breakfasts.