When the city’s planning commission votes today on Columbia University’s plan to build on 17 acres in West Harlem, it is expected to sidestep the question of what role eminent domain could play in the project.

The $6 billion plan’s footprint currently includes some land occupied by gas stations and storage facilities that Columbia has been unable to purchase. In all, four companies or individuals have not sold their property to the university.

How, or whether, Columbia will obtain the title to those properties remains unclear. It has pledged not to ask the state to invoke eminent domain to evict tenants living in residential apartments nearby, but it has not made such a promise to the commercial property owners.

But eminent domain is not proving a sticking point with the city’s planning commission, which is made up of appointees of Mayor Bloomberg and will likely approve Columbia’s plan at today’s hearing. In remarks earlier this month, the chairwoman of the planning commission, Amanda Burden, said the role of eminent domain should be left up to the Empire State Development Corporation, which is controlled by Governor Spitzer.

One lawyer opposing the plan is criticizing the planning commission’s seeming unwillingness to stake out a position on whether eminent domain should be used to benefit Columbia University, a private institution.

“They should find out whether eminent domain will be an aspect of this,” the lawyer, Norman Siegel, said. “But they’re reluctant to enter into the fray about the merits of eminent domain both on the Columbia plan and in general. So they’re punting to the state.”

If the state were to use eminent domain to condemn the commercial property in the footprint, it would likely need to prove the neighborhood is blighted. This would be difficult, critics say, in an area where rents are on the rise and new stores and private investment are visible on streets considered unsafe a decade ago.

Critics of eminent domain say the state’s condemnation of property — no matter how small — in a dynamic neighborhood for a private development would be a heavy-handed abuse of the state’s power.

This use of eminent domain was made possible by the Supreme Court’s 2005 decision of Kelo v. New London, which allows a city to invoke eminent domain for the sake of private economic development.

Columbia’s expansion project, which has been in the planning stages for about five years, calls for new student housing, classrooms, and laboratory space on 17 acres, just north of its existing Morningside Heights campus. The proposal has the support of the Manhattan president, Scott Stringer, but has drawn the opposition of the community board and some local residents who are worried about the expansion’s effect on the availability of housing and jobs. It would still need approval by the City Council to move forward.

One of the commercial landowners, Tuck-It-Away storage, has proposed a land swap with Columbia that would give the university control over the 400,000 square feet of property it wants from the company, a lobbyist for the storage company, Richard Lipsky, said.

It is unclear whether Columbia is interested or whether the other storage company with land in the area, Hudson North American, or the two gas station owners would go along.

A spokeswoman for Columbia did not return a call for comment.