Mayor Linda Thompson will join the developer for the 2 p.m. event, said David Butcher, the company's president.
The commonwealth's largest state-government-relations law practice — Buchanan Ingersoll & Rooney — moved in last month. The firm is the building's lead tenant.
Buchanan will occupy nearly two-thirds of the 50,000-square-foot building, which also will include First National Bank of Pennsylvania's regional headquarters.
The bank began moving in this week. Together, the two anchors employ about 110 people at the Second and State building, Butcher said.
Two other government-relations businesses — Community Networking Resources and Arena Strategies — have leased a combined 3,500 square feet on the second floor, Butcher said. About 500 square feet remains unoccupied.
With this office building winding down, WCI could be shifting its attention back to residential development.
Since 2005, WCI has been buying and renovating residential properties in the Olde Uptown neighborhood, which is near the Governor's Residence. The area is bordered by Muench, Maclay, Second and Third streets.
"We're trying to figure out what's next," Butcher said. "We want to get this wrapped up. We'll know more by the end of the year."
The firm's focus will remain on Harrisburg, he said.
"There is an opportunity for converting (Class) B or C office buildings to residential," Butcher said. "There is strong demand for multifamily residential. People want to be downtown, but maybe not locked in for a long-term commitment."
A lingering issue is the city's taxes and trying to find creative ways to make projects viable, he said, especially with the lack of incentives.
WCI expects to continue targeting opportunities in the Olde Uptown area around Second and Third streets, Butcher said.