By Blake Brittain

June 17 (Reuters) - AI-based legal technology company AI.Law sued competitor Eve in California federal court on Wednesday for allegedly infringing one of its patents.

AI.Law said in the complaint that Eve's technology infringes a patent covering technology for drafting legal documents with AI assistance. The case is one of the first patent disputes between competitors in the fast-growing legal AI sector.

Spokespeople for Eve did not immediately respond to a request for comment on the lawsuit. AI.Law founder Troy Doucet said in a statement that the company welcomes "competition and innovation in legal AI, tempered appropriately through intellectual property rights."

Reuters' parent company Thomson Reuters, which owns Westlaw, is also a competitor in the legal technology field.

San Francisco-based Eve provides several AI-based tools for plaintiffs' law firms, including tools for evaluating new cases, drafting documents, generating medical chronologies, and sending and responding to discovery requests. The startup was valued at $1 billion last year after a round of funding from venture capital firms including Spark Capital and Andreessen Horowitz.

Ohio-based AI.Law said in the complaint that its competing platform features more than 30 AI-powered tools for tasks including drafting motions and demand letters. The lawsuit said that Eve's platform infringes an AI.Law patent covering a method for "using artificial intelligence to transform unstructured materials into long-form, properly formatted documents."

AI.Law requested an unspecified amount of monetary damages for Eve's alleged infringement.

The case is www.ai.law Corp v. Butler Labs Inc d/b/a Eve Legal, U.S. District Court for the Northern District of California, No. 3:26-cv-05930.

For AI.Law: Steven Ritcheson and Jacqueline Burt of Insight PLC

For Eve: attorney information not yet available

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