(Reuters) -Thomson Reuters said on Monday it had agreed to acquire Casetext, a legal startup with an artificial intelligence-powered assistant for law professionals, in a $650 million all-cash deal. One of Casetext's key products is CoCounsel, an AI legal assistant launched in 2023 and powered by GPT-4 that delivers document review, legal research memos, deposition preparation, and contract analysis in minutes, Thomson Reuters said in a statement. The deal is expected to close in the second half of 2023, subject to specified regulatory approvals and customary closing conditions