Amtrak quietly selected three potential “master developers” for the renovation of the massive transit hub — and won’t say whether it will make public its criteria for picking the winner, which Penn Station czar Andy Byford previously said will be subject to the final approval of President Trump.

In an unpublicized, 25-word update posted to the Amtrak Vendor Portal on Tuesday, the federal railroad revealed the names of three companies that answered its call to express interest in building the mega-project — with no additional information.

When Amtrak invited companies to get into the Penn redevelopment game last year, it said it would issue a request for proposals once it had a shortlist of interested parties.