Cornell University won’t be able to appeal an order allowing a jury to hear a portion of a lawsuit challenging how the college managed its employees’ retirement savings.

A federal judge in New York Oct. 11 denied the university’s request to immediately appeal his decision allowing Cornell employees to send to a jury their claim holding plan committee members personally liable for their retirement plan losses.

If the case goes all the way to trial, Cornell will become the first employer to face a jury defending claims related to how it managed its retirement plan under the Employee Retirement Income...