Ellen's Irish Pub, also known as the Ben Bow Restaurant, for years a lively watering hole for Dupont Circle area residents, must close April 1, owner Ellen Donlan said yesterday.

Donlan said she received word of the closing March 2 in a letter handdelivered to her as she was serving drinks at the old bar she has owned for 15 years. A $200,000 offer she said she made to Jeffrey N. Cohen, the owner of the building at 1636 Connecticut Ave. NW, to buy the building was turned down yesterday.

"I feel sad and very nervous about it," she said, as she served a group of alternately angry, then nostalgic customers at the bar yesterday afternoon.

"I can see it coming, luv," she said. "We could fight the other owner of the building, but I think this guy Cohen is going to plow us under."

Cohen told a reporter he bought the three-story building from the American Psychiatric Association last month, and that he planned to use most of the building for office space. He said plans might include an ice cream parlor instead of the bar.

Although Cohen said he wasn't ready to disclose all his plans for the building, he said, "There definitely won't be a bar there."

"We're using the space for ourselves. There is no room for the pub," Cohen said.

Donlan and pub regulars staged rallies and lobbied the city government in October and November when the American Psychiatric Association, then owners of the building, planned to demolish the structure. On Nov. 4, the Joint Committee on Landmarks of the National Capital gave the pub a 180-day reprieve from destruction.

Cohen, the new owner, told a reporter that he doesn't want to raze the building, but to rehabilitate it.

As they gathered around the bar yesterday, several pub regulars said they feared that once the bar was gone, the new owner would tear down the structure. Thus, another old building, and to some, a way of life, would be lost to Washington.

In the meantime, however, Donlan said she was planning "a hell of a St. Patrick's Day party with corned beef and cabbage and all the Irish trimmings.

"I'm still going to fight him," she said, still wondering how she could fight eviction, "but he's not going to kill my St. Patrick's Day."