UPDATE 1-Impregilo says Panama bid tops in tech appraisal

* Panama Canal expansion seen costing $3.7 billion

* No details on two other bidders technical appraisal

* Naples court ruling on sequestration delayed to Oct 1 (Adds comments on Naples court delay)

SANTA MARGHERITA, Italy , June 12 (Reuters) - A consortium including Italy's Impregilo SpA (IPGI.MI) has obtained top marks in the technical appraisal of bids to expand the Panama Canal, Impregilo's chairman said on Friday.

Impregilo has said the whole Panama expansion project is worth $3.7 billion and it has a potential 37 percent stake in any contract.

"The (tender) envelopes will be opened on June 29," Chairman Massimo Ponzellini said during a conference at a meeting of the Confindustria employers association.

"We know we have obtained the maximum technical points. We hope to win the contest," he said, without elaborating.

Brokers have cited order news, including the Panama project, as supporting a rise in Impregilo's shares. They closed on Friday up 4.17 percent at 2.56 euros.

Impregilo's consortium partners are Spain's Sacyr Vallehermoso SA (SVO.MC), Portugal's Somague, Belgium's Jan de Nul and Panama's Cusa.

Two other consortiums are on the short list.

The first is the CANAL grouping including Spain's ACS SA (ACS.MC), Acciona SA (ANA.MC) and Germany's Hochtief AG (HOTG.DE). The second is a Japanese-U.S. group led by the privately held Bechtel.

Ponzellini also commented on the sequestration of Impregilo assets as part of a long-running investigation into a refuse-burning plant at Acerra near Naples.

"Today there should have been the decision by the reexamination court of Naples on the sequestration or not of 400 million euros, but the decision has been put back to Oct. 1," he said on the margins of a conference.

In April, Italy's highest court ordered the release of 302 million euros in assets out of a 750 million euro total sequestered and sent the case back to a Naples court to decide on the rest of the sequestration. (Reporting by Cristina Carlevaro; writing by Nigel Tutt; Editing by Hans Peters and Gerald E. McCormick)