Gerard Sweeney has jumped out of an airplane, so maybe rappelling down the side of his company's 31-story building for charity wasn't such a big deal.

Except for the wind.

"I was a little scared," Sweeney, 58, chief executive of Brandywine Realty Trust, admitted moments after his windy descent Thursday, although he was all smiles for his cheering colleagues.

"This is pure philanthropy," he said, describing why his company is providing its building and funds to the Philadelphia Outward Bound School for its fund-raiser.

By the time the event ends Friday, 130 people will have rappelled down the side of One Logan Square to raise between $200,000 and $250,000 for the group, which organizes outdoor expeditions to teach team-building, leadership, and courage to young people, many from the region's poorest neighborhoods.

But experts say corporate philanthropy is usually about more than just philanthropy.

"There has to be credibility and visibility," said Laura Otten, director of the Nonprofit Center at La Salle University.

For companies, she said, "there seems to be much more emphasis on what 'it's going to do for us.' They are being very strategic to make sure there is some kind of a return."

Marketing, brand-building, and human-resource considerations all count as companies build corporate-giving strategies.

All of that came into play for one Outward Bound sponsor, Aberdeen Asset Management P.L.C., a Scottish financial-services company that has its American headquarters in Philadelphia. Aberdeen also sponsors the Dad Vail Regatta.

"Our philosophy is two-pronged," said Jeffrey "J.D." Hall, a marketing manager in Philadelphia. "It's as much about brand-building as it is good corporate citizenship."

That's particularly important for a foreign company, said Hall's boss.

"It demonstrates an element of commitment," said Andrew Kelly, Americas marketing head. "Some companies that come here and try to take shortcuts to become more of a local brand fall flat on their faces."

Aberdeen kicked in between $10,000 and $15,000 to be an Outward Bound "Peak" sponsor, and in return will get a booth at the bottom of the building and five slots for employees to go over the edge.

At Aberdeen, those slots were chosen by raffle. Hall got lucky.

"We have a very active group of employees. People are very interested in sports," he said.

Besides matching employees' donations up to $500, Aberdeen gives them two paid days a year for volunteer work for their personal charities or through company initiatives.

"It makes employees want to work for a company like that," said Aberdeen's human-resources leader, Marika Tooze.

Both Otten and Debra Kahn, executive director of the Philanthropy Network of Greater Philadelphia, an association for philanthropic organizations, say they are seeing corporations increasingly emphasize volunteerism as part of their philanthropic strategies.

It comes at a time when corporate giving is falling, according to Giving USA's closely watched annual report. In 2013, corporate giving declined 2 percent to $17.9 billion nationally. By contrast, individual giving was up.

"What we are seeing and hearing is that corporations are inclined to give more volunteers - both skilled and unskilled volunteers," Otten said.

"Employees look for those opportunities," Kahn said. "Younger employees like companies with civic spirit.

"It can be good for their professional development. They develop themselves in a different arena. It helps employees understand the wider world," she said. In turn, the employees bring skills that benefit the charity.

Connections also count. For Sweeney, the tie comes through stepson Lee Emery, who works at Outward Bound.

Aberdeen's chief operating officer, Andrew Smith, is on Outward Bound's board, although, Hall said, groups at each office vote on which charity to back.

"We need our board members to open the doors. Then we can go and talk to the decision-makers," said Katie Newsom Pastuszek, executive director of Outward Bound.

Corporate sponsors, she said, kick in the big chunks of money that make it easier to envision meeting the final goal, particularly useful to cover the $90,000 it costs to produce the event. Then it isn't as daunting to raise the rest in $2,000 increments from the rappellers.

"The corporate entities like the exposure," she said. "I think they like that it is exposure from a very good cause - changing lives through challenge and discovery. From a funding perspective, it's a win-win."