Shares in UK ingredients company Tate & Lyle plunged in morning trade today (23 September) after the company revealed that it has lost its US sucralose patent-infringement case.

Shares had fallen 13.88% at 10.43 am (BST) to 358.25 pence (US$6.67), making Tate & Lyle the biggest faller in the FTSE 250.

The company had launched a patent lawsuit against certain manufacturers and importers of Chinese sucralose in the US, including Changzhou Niutang, one of the largest global manufacturers of sucralose, and its US subsidiary, US Niutang.

However, a US International Trade Commission (ITC) administrative law judge concluded that Niutang and the other unnamed defendants did not violate any patents for manufacturing the sweetener sucralose, as claimed by Tate & Lyle.

Tate & Lyle manufactures sucralose under the brand name Splenda. The artificial sweetener accounts for almost a quarter of the group's operating profits. In the year to 31 March, Splenda contributed GBP66m to the group's total operating profits of GBP286m.

A spokesperson for Tate & Lyle told just-food that the company intends to appeal the ruling.

"We are appealing the current ruling. The Judges Commission is expected to come back with a report in January 2009 and that will be the final stage in the case," the spokesperson commented.