The sealed bid auction of the 22,800-square-foot waterfront estate situated on the North end of Mercer Island on Roanoke Way has been extended to June 30, according to Sheldon Good & Company, the Chicago-based real estate firm which is conducting the sale.

Reportedly, a suitable buyer has not been found. The extended deadline is a result of the seller’s objective to receive a contingent-free contract, said Craig Post of Sheldon Good. According to other news reports, the bids received were all contingent on the sale of other properties, which is not what the buyers want.

The home was previously listed at $40 million and was on the conventional real estate market for four years. It was originally offered at auction earlier this year with a qualified minimum bid of $15 million. The minimum bid is now at or above $12 million.

The luxury property is on two waterfront acres and includes two master suites, three kitchens, a personal workout gym, two wine cellars and an indoor 66-foot salt water pool. There are gold leaf cove ceilings, Italian marble and hardwood floors and a 12-foot Chihuly chandelier in the entry. There is a greenhouse, a stocked trout pond, and a deep water dock that can accommodate a 140-foot yacht.

Interested parties should go to www.sheldongood.com or see previous Reporter stories at www.mi-reporter.com.