Another big-name company is heading to the Seaport.

Boston Consulting Group said Friday that it has signed a lease to occupy more than half of a 13-story office building now under construction on Pier 4. BCG will move there when the building opens in 2018, consolidating its 700 local employees from a pair of offices in the heart of downtown.

The consulting giant is the latest in a series of blue-chip professional services companies to decamp to new buildings across Fort Point Channel, following accounting firm PwC and law firm Goodwin Procter, which is moving into 100 Northern Ave. this weekend. Like those companies, BCG will be the anchor tenant in a brand-new building, taking 202,000 of the 370,000 square feet of the mid-rise that Tishman Speyer is building on Pier 4.

For the consulting giant, the move is a chance to design new, top-of-the-line space explicitly for its 700 employees, said Simon Bartletta, managing director of BCG’s Boston office.

“It gave us this canvas to design the office that we wanted,’’ Bartletta said. “It’s a flagship building in a new location where we could think about the office of the future.’’

BCG had been one of the largest potential office tenants on the market in downtown Boston this year. Signing with Tishman takes BCG off the table for several rival office developers, and leaves just three or four other companies looking for 200,000 square feet or more in downtown Boston right now, real estate sources say.

That shortage could pose a challenge for several big office towers that are now in development. While Tishman, with the backing of two Chinese insurance companies, launched construction on its Pier 4 building earlier this year without tenants lined up, most other developers say they won’t break ground on an office tower until about half the space in the building is spoken for, to avoid the overbuilding that Boston and other cities have seen late in past real estate cycles.

For BCG, the chance to help design a new building, and to move into the burgeoning Seaport, was attractive, Bartletta said. The company will combine its local Boston office, now at 53 State St., and a global services office, at One Beacon St., into Pier 4, with room to keep expanding over the 15-year term of the lease.

“We’re constantly hiring and growing the size of the business,’’ Bartletta said. “We’ll be bigger two years from now than we are today, and bigger in the years after that.’’

Bartletta acknowledged that transportation into the Seaport, compared with its current sites in transit-rich downtown, is a bit of a concern. But developers, Seaport companies, and city officials have been talking about better ways to move people in and out of the booming business district, he said. And Bartletta said his firm plans to lend its expertise to those conversations.

“We love solving hard problems,’’ he said. “I envision us being more of a participant in that.’’

Tim Logan can be reached at tim.logan@globe.com. Follow him on Twitter at @bytimlogan.