It was the first day of his freshman year, 1980, when David Berray ’84 stuck his head out of his fourth story window at the corner of Wright Hall, surveyed his surroundings, and established what was to become something of a reputation.

“Hey, what are you doing?” he called to a stranger two floors below.

“Why don’t you come on up and have a drink?”

It was the first of many invitations Berray would issue into his world of late-night bridge, classy parties, Sinatra music and swing dance.

The bon vivant of Saybrook who seemed always ready for the next adventure, Berray would go on to become a successful banking executive and doting father, equally suited for sophisticated evenings out and weekend hikes with his children.

He was a cosmopolitan gentleman who drank Dewar’s scotch and ran companies in Hong Kong and New York, but his dream was to move his family back to Millbrook, the small town in New York where he grew up.

Berray was also known as a devoted friend. Rather than going to his office at MoneyLine, a financial technology company where he served as vice president and chief operating officer, on Sept. 11, Berray chose to attend a conference where a friend was speaking.

He told his wife Alison “I’ll see you later,” as he left for the 8:30 breakfast meeting at the World Trade Center’s Windows on the World restaurant.

Like the other 113 people in the restaurant that morning, Berray, 39, remains missing, Alison Berray said. His family is planning a memorial service Oct. 8, 11 days before his 40th birthday.

“He was full of energy, brilliant,” Alison said. “He was one of those kind of people for whom everything can be done, where no is not an answer.”

Berray grew up in Millbrook before attending the Hotchkiss School in Lakewood, Conn. Before arriving at Yale, Berray spent a year teaching skiing in Aspen, a city he arrived in largely by chance after hitchhiking across the country.

At Yale, Berray made a name for himself around Saybrook, serving on the student activities committee, playing intramurals and hosting fancy parties.

He loved to bring friends home to Millbrook on weekends, where he would often pop a bottle of champagne and fix a meal of shrimp over fettuccini as a fire crackled in the kitchen fireplace and Ella Fitzgerald played on the stereo.

“He had a sense of style and he almost seemed to be of a different generation,” said Sara Cavendish ’84, the stranger from downstairs who would become his closest friend in college.

He loved entertaining and grew to be known for it.

“When I think of David, I think of parties — cocktail parties, charity balls, a bon mot,” Tres Arnett ’84, one of Berray’s closest friends, wrote in an e-mail. “He was more George W. Bush than Joe Lieberman.”

But the well-dressed socialite was also a dedicated student, whose seemingly effortless academic career inspired a dream to one day teach.

The economics major who could often be seen in Cross Campus Library with his feet up on a desk and an economics book across his lap went on to earn an MBA from New York University’s Stern School of Business.

After spending 10 years working at Bankers Trust in Hong Kong, Berray returned to school last year, earning a master’s degree from MIT’s Sloan School of Management. He was thinking about going to law school.

“David wasn’t going to just keep doing the same old thing,” said Lee Barba, chief executive of Telescan, a financial technology company where Berray worked as chief operating officer until last winter. “He would try to see what was coming around the bend, the next curve, and get involved in it.”

Berray left Telescan for MoneyLine in January, in part because it promised less travel, and thus more time for his family. He was still trying to find a job that would allow him to live in Millbrook full-time, Alison Berray said.

At work, he showed off photo albums of Alison and his two children, Lauren and Lachlan. He kept up many hobbies of his younger days, friends said, and he managed to fit them into his new role as doting husband and father.

“In one sense, he was kind of a classic Wall Street boy,” said David Stack ’79, a friend who lives in Millbrook. “He loved his cigars and his shooting and his fishing. When his children came he didn’t give up any of that, but from the first moment he altered all of that focus so that it was all part of and took second seat to his family.”

For the Berrays, that meant fitting their bicycles with baby seats, and taking Lauren and Lachlan hiking as soon as they were old enough.

They returned to Millbrook on weekends and in the summers, staying in the same converted mill house by a stream where David was raised. Lately, he had been doing projects around the house that his father was no longer able to do.

Weekends often included taking the children on hikes or packing lunch and taking long car trips, sometimes to friends’ farms where Lauren and Lachlan could ride horses and play with the animals.

“He just seemed to be enjoying himself, his family, his friends, and his work more and more with each passing year,” Cavendish said. “He settled into a really ideal, comfortable life.”

His hair was beginning to gray, said Cavendish, but he was in peak physical shape. He and Alison had recently returned from a trip to Asia, where they had climbed Mount Fuji.

Barba recalled that Berray, who went to the gym each morning, used to tease him about becoming more athletic.

“He had taken all these tests,” Barba said. “He was in perfect shape. He was supposed to live to be 100.”

He wanted to “live forever and be healthy to go hiking and give the best for his children,” Alison Berray said. “He lived every day to the fullest. He got up early in the morning and if he didn’t do his thousand things by the end of the day, he felt he didn’t accomplish anything. He had big dreams.”

The family asks that thoughts and memories of David Berray be sent to: David M. Berray Children’s Fund, P.O. Box 548, Millbrook, N.Y. 12545.