How important is the sugar substitute sucralose to the fortunes of the British food company Tate & Lyle? Very, very important: On Tuesday, Tate & Lyle’s stock price fell 5 percent on news that the International Trade Commission had ruled against an appeal by Tate & Lyle and given the go-ahead to four Chinese manufacturers of copycat versions of Tate’s Splenda sweetener. Splenda accounts for about 20 percent of Tate & Lyle’s profits, according to Reuters.

Two of the Chinese manufacturers were represented by a team of Bingham McCutchen lawyers headed by Gary Hnath. Kenyon & Kenyon and Fish & Richardson represented the other two. Tate & Lyle had Thomas Jarvis at Finnegan, Henderson, Farabow, Garrett & Dunner, who didn’t return our call for comment.

In Tuesday’s order, the ITC reviewed its September 2008 ruling (we wrote about it here) that the Chinese manufacturers were not infringing Tate & Lyle process patents, upheld its findings, and closed the investigation. Tate & Lyle told Reuters that it is reviewing the ITC ruling and considering an appeal to the Federal Circuit.

Bingham’s Hnath told the Litigation Daily that the ITC ruling was “extremely significant.” Customers had been waiting to buy sucralose products from the Chinese manufacturers, he said, “because they were concerned about the threat of litigation from Tate & Lyle.” Now that threat is removed, Hnath said.