Only behind-closed-doors bidding took place for the unprecedented collection of objects, which a US court ordered must be sold as a single lot and kept together.

That stipulation and what Guernsey's auctioneers estimate will be the $189 million price tag have made this an unusual -- and possibly difficult -- sale.

Premier Exhibitions, Inc, which is selling the artifacts, announced Tuesday that more time was needed and that a press conference which had been expected to see the auction winner revealed "will be rescheduled."

"The Company announced today that it is in discussions with multiple parties for the purchase of its Titanic artifacts collection. In order for the Company to settle on the most appropriate bidder and maximize the ultimate value of the artifacts for shareholders, it will conduct these negotiations and due diligence in confidence," Premier Exhibitions said in a statement.

The relics on sale range from a 17-ton piece of Titanic's hull to china used to serve first-class passengers on the doomed ship, which sank after hitting an iceberg in the north Atlantic 100 years ago, killing more than 1,500 people.