EXCO (NYSE:XCO) Chief Executive Officer, Douglas Miller dropped a buyout offer to $18.50 from $20.50 a share.Miller has submitted a downwardly revised buyout offer to the company, citing people with knowledge of the matter. The new offer is valued at $18.50 a share, and adds a stock component, while the previous bid, made in October, was for $20.50 a share in cash.A committee of Exco’s board is evaluating the offer and possibly will make a decision within days. Miller's submission last week didn't consist of commited financing for the transaction.EXCO Resources (NYSE:XCO) has a potential upside of 36.3% based on a current price of $16.65 and an average consensus analyst price target of $22.70.