Under the offer, Illinois-based Ingredion will pay up to 615p per share for London-listed Tate & Lyle, including 595p in cash and dividend payments due on top.
The deal values Tate at £2.7 billion, or £3.7 billion including debts, and follows a number of earlier proposals by Ingredion.
It comes after Tate’s shares have been under pressure over the past year, with the firm warning over full-year profits last October and revealing a 10% drop in first half profits in November.
David Hearn, the chairman of Tate & Lyle, said: “Looking forward, we believe the next chapter with Ingredion will create a business with even greater potential, greater scale, and increased investment in innovation in support of customers.
“The board of Tate & Lyle believes Ingredion’s offer represents an attractive opportunity for shareholders to crystallise value in cash, and that it will be an excellent steward of Tate & Lyle.”
It marks the latest blow to the London market after a spate of swoops for UK companies by foreign firms.
Tate sold its sugar division – including the Golden Syrup factory in London – to American Sugar Refining in 2010 (Sean Dempsey/PA)
William Hill owner Evoke last week agreed a £243.1 million takeover by Greek gambling firm Bally’s Intralot, while laboratory testing company Intertek’s board recently gave its initial backing to a £9.4 billion proposal from Swedish firm EQT.
Insurance firm Beazley and asset manager Schroders have also agreed deals to be taken private this year.
Tate’s performance has flagged in recent years as customer demand has dropped and costs increased.
On announcing the deal, Tate said “over the last year, the operating environment for ingredients companies and their customers has deteriorated, with consumer sentiment weakening across all major regions”.
Tate & Lyle is listed on the FTSE 250 Index and was first founded more than 165 years ago.
While the brand is known for sugar products, Tate sold its sugar division – including the Golden Syrup factory in London – to American Sugar Refining for £211 million in 2010.
The deal allowed the US firm to continue using the brand on its sugar products and left Tate & Lyle focused on sweeteners and its industrial food ingredients division.
Tate last year bought food and drink ingredients business CP Kelco in a deal worth around £1.4 billion.
The firm’s US suitor, Ingredion, employs more than 12,000 people worldwide.
It makes sweeteners, starches, nutritional ingredients and biomaterials that are used in food and drinks, as well as paper and pharmaceuticals.
The firm traces its roots back more than 100 years and has grown by a series of acquisitions in the US and overseas.
For Ingredion, the acquisition will boost its geographic reach further and widen its portfolio, into areas such as texturants, sugar reduction, and fortification.
The companies are set to drive cost savings of around 130 million US dollars (£97.5 million) a year by the end of 2030 following the takeover.
Jim Zallie, chairman and chief executive of Ingredion, said: “Combining Ingredion and Tate & Lyle’s complementary portfolios creates a global leader in ingredient solutions with the expertise and geographic reach to help shape the future of food.
“The combined business will be better positioned to serve customers’ needs for the development of great-tasting, healthier and affordable food products that consumers demand.
“This compelling combination will create exciting new possibilities for employees and generate significant value for all stakeholders.”