A New York judge on Friday upheld President-elect Donald J. Trump’s criminal conviction but signaled that he was inclined to spare him any punishment, a striking development in a case that had spotlighted an array of embarrassing misdeeds and imperiled the former and future president’s freedom.

The judge, Juan M. Merchan, indicated that he favored a so-called unconditional discharge of Mr. Trump’s sentence, a rare and lenient alternative to jail or probation. He set a sentencing date of Jan. 10.

An unconditional discharge would cement Mr. Trump’s status as a felon just weeks before his inauguration — he would be the first to carry that dubious designation into the presidency — even as it would water down the consequences for his crimes.

Unlike a conditional discharge, which allows defendants to walk free if they meet certain requirements, such as maintaining employment or paying restitution, an unconditional discharge would come without strings attached.

Mr. Trump, who is now expected to ask an appeals court to intervene and postpone the sentencing, faces up to four years in prison. A Manhattan jury convicted him in May on 34 counts of falsifying business records, concluding that he had sought to cover up a sex scandal that threatened to derail his 2016 campaign for president.

This is a developing story and will be updated.