J. Paul Getty Museum officials announced today that they were returning to Italy 26 antiquities now believed to be looted. But the officials said they were breaking off negotiations over the fate of 20 more. In a letter dated Nov. 20, museum director Michael Brand told Italian Cultural Minister Francesco Rutelli that he was "deeply saddened" the two sides couldn't come to a complete agreement. He noted that the museum was willing to give back some of its most important pieces and had even offered to transfer full title to Italy of its signature figure of the goddess Aphrodite -- as long as further research into its origins could be jointly investigated. The letter cites the source of the deadlock as the museum's refusal to return a prized bronze statue of a young Greek athlete, which along with the Aphrodite are considered the Getty's marquee pieces. "We regret that this object stands in the way of an accord, but we are very comfortable with our decision to retain it," Brand wrote, adding that the Italian courts had held the statue was found in international waters. The Aphrodite and bronze are at the top of a list of 46 objects that Italian cultural officials have been demanding back based on evidence presented in the ongoing criminal trial of former Getty antiquities curator Marion True. Italian cultural officials couldn't be reached today, but one Italian source familiar with the negotiations said a top cultural official told Getty representatives last week it was "all or nothing." The source said Italian officials agreed that the talks had collapsed and blamed the Getty for having been "stubborn" and "thin skinned." The Getty's conflict with Italy stands in stark contrast with similar talks with museums in New York and Boston, which have agreed to return major antiquities in return for revolving loans of similar art from Italy. The Times reported last week that Italian cultural officials have become so frustrated with what they call the Getty's "commercial" approach to negotiations that they were considering a cultural embargo, something the Italian source said was now likely to proceed.