The UK Competition and Markets Authority is referring T&L Sugars' proposed acquisition of Tereos' UK assets to the second "phase" of its investigation.

According to the CMA, Tate & Lyle Sugars did not comply with its request to respond to the regulator's concerns published following the release of its preliminary findings on 8 March.

Both T&L Sugars and Tereos had been given until 15 March to provide evidence to satisfy the watchdog's concerns.

Explaining the rationale behind its move toward the second phase of the probe, Sorcha O'Carroll, senior director of mergers at the CMA, said T&L Sugars "informed the CMA that they would not offer such undertakings".

The competition regulator now plans to complete the "in-depth" investigation by 5 September.

Just Food has asked both T&L Sugars and Tereos for comment on the CMA's latest decision.

Following the first phase, the anti-trust body found that the deal showed risks of inflated sugar prices for UK consumers, and “a substantial lessening of competition”.

Both T&L Sugars and Tereos only face competition from one other UK business, British Sugar, and the acquisition would only make the market more "concentrated", O'Carroll said at the time.

A more concentrated market would mean retailers would have to pay higher prices, which would then affect prices for the consumer.

O'Carroll added that the deal "would bring together two of the three players in the UK sugar sector, reducing competition and choice further for people and businesses".

Tereos' UK and Ireland unit packs and distributes Whitworths' branded and private-label sugar in Normanton, West Yorkshire.

T&L Sugars, owned by ASR Group International, manufactures a portfolio of sugar and sweetener products under the Tate and Lyle name as well as own-label goods at its London HQ. It sells to UK supermarkets, grocery wholesalers and foodservice.