PHILADELPHIA--Secret Service agents investigated what they considered a possible threat against the life of President Reagan in a column that appeared in the Daily Pennsylvanian. the University of Pennsylvania's student-run newspaper.

The Secret Service and the U.S. Attorney's Office decided that the columnist. Dominic F. Manno, "is not dangerous at this time." Kevin M Tucker, the special agent in charge of the investigation, said yesterday.

Manno's column appeared on April 1. two days after John W. Hinckley allegedly attempted to assassinate Reagan. "Too bad he missed. That's the result of sending an amateur to do a professional job. I hope he dies," Manno wrote.

Hinckley "just seems to be someone who could get upset and angry enough about the political system to use a bullet to cancel out the ballot. A lot of people feel that way about the system. Including me," Manno wrote.

The Pennsylvanian cancelled Manno's weekly column because of the incident. Andrew J. Kirtzman, executive editor of the Daily Pennsylvanian, said yesterday. "We regret printing the column. The Daily Pennsylvanian has standards which this column did not meet," he added.

Manno said he resigned from the paper after it's editors stripped him of his column because he did not want to be part of a "paper that didn't stand firm for its first amendment rights."

Manno said he regrets writing the column. adding "I let my hatred for Reagan the politician overwhelm my respect for Reagan the man."

Expensive Lawyers

The paper's managing board has received "letters and phone calls from lunatics all across the country" about the column, one editor said, adding that the incident will cost the paper over $1000 in legal costs.

Tucker said the Secret Service did not question the Daily Pennsylvanian's right to print the article.