If getting to Bloomingdale’s via the 4, 5, and 6 lines seems more difficult than usual this holiday season, it may be due to an unresolved conflict between the Metropolitan Transportation Authority and Vornado Realty Trust that has closed a subway entrance at one of the city’s busiest stations.

Because of a safety issue raised by the MTA, the sole entrance on the south side of the station, at 59th Street and Lexington Avenue, has been closed since it was constructed by Vornado about a year ago. The entrance leads into the building at 731 Lexington Ave., home of the headquarters of Bloomberg LLP and many retail businesses.

The possibility that ice could fall from eaves on the 54-story building makes the entrance a safety hazard for riders entering and exiting the station, according to the MTA, which closed the entrance before it was supposed to open last February. The dispute has lasted for almost a year because of disagreement about which party is responsible for preventing the falling ice.

Vornado has refused to make the changes to the station entrance demanded by the MTA, arguing that the original entrance plans received MTA approval. The MTA is retaining a $1 million bond that belongs to Vornado until the issue is solved.

In the midst of an unseasonably warm winter that has produced little fear of falling ice, a spokesman for the MTA said an agreement is currently being reviewed by both parties. “We’re hoping to open very shortly, we just don’t know when,” the spokesman, James Anyasi, said.

Upper East side residents have expressed skepticism about the MTA’s claims of progress. “I’ve heard that the attorneys for the various parties are talking,” the chairman of the transportation committee of Community Board 6, Lou Sepersky, said.”That’s the same recitation that I heard two years ago when I first got involved.”

Community Board 6 issued a resolution last week urging the parties to negotiate a prompt settlement of the sidewalk safety issue, and requested that the Department of Buildings get involved if necessary.

In a worst-case scenario, the city could order Vornado to vacate the building if it is found in violation of the zoning easement, which allows the MTA to run a property owned by Vornado.

Local leaders and community members say they are less concerned with which side is to blame for the closure than with restoring service at a crowded station during the busiest time of the year.

“The Lexington line is the most heavily utilized line in the subway system,” City Council Member Jessica Lappin, who represents the area, said. “Restricting the circulation of passengers there is bad for safety and for commerce. This seems ridiculous. There’s got to be a way to get both sides together and reopen the station.”

“There are situations where there are up to 10 people waiting behind one turnstile,” the chairman of Community Board 6, Lyle Frank, said, raising the concern that subway riders might not be able to exit the station quickly in an emergency situation.