BRUSSELS, Oct 12 (Reuters) - Nvidia"s (NVDA.O) $54 billion bid for British chip designer ARM is expected to face an extended EU antitrust investigation after concessions offered last week failed to address competition concerns, three people familiar with the matter said. An EU investigation would be the second setback for Nvidia coming two months after Britain"s antitrust agency warned that the deal for the country"s most important technology company could damage competition and weaken rivals. read more The European Commission is scheduled to end its preliminary review on Oct. 27 and a four-month investigation into the deal would now follow, the people told Reuters said. A spokesperson for the Commission declined to comment. BRUSSELS, Oct 12 (Reuters) - Nvidia"s (NVDA.O) $54 billion bid for British chip designer ARM is expected to face an extended EU antitrust investigation after concessions offered last week failed to address competition concerns, three people familiar with the matter said. An EU investigation would be the second setback for Nvidia coming two months after Britain"s antitrust agency warned that the deal for the country"s most important technology company could damage competition and weaken rivals. read more The European Commission is scheduled to end its preliminary review on Oct. 27 and a four-month investigation into the deal would now follow, the people told Reuters said. A spokesperson for the Commission declined to comment. "The regulatory process is confidential. The transaction will help to transform Arm and boost competition and innovation, including in the UK," Nvidia Corp, a U.S. technology firm headquartered in Silicon Valley, said. The world"s biggest maker of graphics and artificial intelligence (AI) chips has offered "behavioural remedies" to the Commission, the people said, without providing details. Such remedies usually refer to pledges by companies to take measures aimed at preserving competition. Nvidia has said it would maintain ARM as a neutral technology supplier in a bid to allay concerns from customers such as Qualcomm Inc (QCOM.O), Samsung Electronics Co Ltd (005930.KS) and Apple Inc (AAPL.O). BRUSSELS, Oct 12 (Reuters) - Nvidia"s (NVDA.O) $54 billion bid for British chip designer ARM is expected to face an extended EU antitrust investigation after concessions offered last week failed to address competition concerns, three people familiar with the matter said. An EU investigation would be the second setback for Nvidia coming two months after Britain"s antitrust agency warned that the deal for the country"s most important technology company could damage competition and weaken rivals. read more The European Commission is scheduled to end its preliminary review on Oct. 27 and a four-month investigation into the deal would now follow, the people told Reuters said. A spokesperson for the Commission declined to comment. "The regulatory process is confidential. The transaction will help to transform Arm and boost competition and innovation, including in the UK," Nvidia Corp, a U.S. technology firm headquartered in Silicon Valley, said. The world"s biggest maker of graphics and artificial intelligence (AI) chips has offered "behavioural remedies" to the Commission, the people said, without providing details. Such remedies usually refer to pledges by companies to take measures aimed at preserving competition. Nvidia has said it would maintain ARM as a neutral technology supplier in a bid to allay concerns from customers such as Qualcomm Inc (QCOM.O), Samsung Electronics Co Ltd (005930.KS) and Apple Inc (AAPL.O). The EU competition enforcer has not sought feedback from rivals and customers on the concessions, indicating that they were not sufficient, the people said. Backers of the deal include ARM customers Broadcom (AVGO.O), MediaTek (2454.TW) and Marvell (MRVL.O).