Harvard and Boston University are both eyeing Allston industrial properties put up for sale on Monday by the debt-ridden Massachusetts Turnpike Authority.

Located south of the Business School and lying adjacent to other Harvard properties, the 91-acre site is the largest single parcel to come to market, bigger even than the adjacent 47-acre Allston Landing North parcel, which harvard bought from the Turnpike for $151 million in 2000.

However, a number of obstacles stand in the way of development—the property is crisscrossed by miles of iron and concrete, cut in two pieces by the turnpike, and dominated by rail lines owned by CSX—which has rights to use the land in perpetuity.

But Harvard has taken on similarly encumbered parcels in the past in the name of long-term planning.

Harvard already owns nearly 300 acres across the river in Allston, land similarly riddled with rail yards and auto body shops—and the site of Harvard’s much celebrated but as-yet undefined campus of the future.

And for now, the University hasn’t stopped shopping across the river.

“I think the right way to think about the University is, we’re not like somebody moving to a new city looking for a house,” said University President Lawrence H. Summers. “We’re always interested if land becomes available for purchase.”

But if Harvard wants the new real estate, known as Allston Landing South, it may need to compete with BU, which has expressed interest in expanding onto the land out of its nearby Charles River Campus.

The land might well be a key piece in Harvard’s long-term Allston planning puzzle—but administrators say the land’s encumbrances and distance from Cambridge mean that the parcel is not a sure bet.

One Man’s Junk...

Like the nearby parcel Harvard already owns, the potential of the new land is severely limited by its tenants, the CSX rail yards and the turnpike itself.

And Harvard is more skeptical about its need for this land than it was at the Turnpike Authority’s last Allston sale.

Sally Zeckhauser, vice president for administration, said Harvard would need to further investigate the property before making a decision to bid.

She said that the land’s distance from Harvard’s campus and its heavy encumbrance make it less attractive than other sites in Allston.

“The land adjacent to the Business School is the part that is of the most interest,” she said. “Northern land is really our primary focus, near Western Ave. This property is south of Western Ave., and our interest is certainly diminished the farther south the land is.”