The Federal Communications Commission’s staff threw up a significant roadblock Wednesday to Comcast Corp. ’s proposed acquisition of Time Warner Cable Inc., recommending a procedural move that could potentially sink one of the media industry’s biggest mergers in years.

The FCC staff reached a conclusion that the best option for the FCC is to issue a “hearing designation order,” according to people familiar with the matter. In effect, that would put the $45.2 billion merger in the hands of an administrative law judge, and would be seen as a strong sign the FCC doesn’t believe the deal is in the public interest.

Comcast and Time Warner Cable may still have an opportunity to weigh in on the matter before the proceeding moves forward, people familiar with the situation said. Those people cautioned that the situation remains fluid and no final decision has been made.

A hearing could be a drawn-out process, and some regulatory experts describe the procedure as a deal-killer, though Comcast would be entitled to make its case for the tie-up.

Comcast executives on Wednesday met with officials at the FCC and the Justice Department, as those regulators’ reviews of the proposed merger enters its final stages.