UBS has downgraded its rating for mining group ENRC from 'buy' to 'neutral' and slashed its target price from 285p to 230p to reflect the latest offer by the firm's founding shareholders and the Kazakhstan government.Earlier this week, the consortium offered 234.3p a share for the miner, well below the 260p-a-share offer made in May.ENRC has said that the new offer "materially undervalues the company" and did not recommend it to shareholders.UBS said: "A 'relationship agreement' in ENRC's IPO documents suggests that the independent committee must approve the formation of a consortium for an offer to be made; but we have questioned the ability to enforce this. "Despite not recommending the offer we believe the consortium is likely to by-pass the independent committee and allow ENRC shareholders to vote on the offer."Meanwhile, the broker reckons that 26% shareholder Kazakhmys could block the deal but is unlikely to do so. It said that under 100m shares, half of Kazakhmys' freefloat or 18% of the total company, would have to vote against the deal to block it (assuming a 100% turnout).However, "due to limited alternatives we believe Kaz shareholders are likely to approve the current offer".