The Canadian oil company seeking permission to build the nearly 1,200-mile-long Keystone XL pipeline filed papers Tuesday to secure rights to build on private land in Nebraska, setting off the latest round of legal battles that have stalled the project.

TransCanada Corp. said Tuesday that it had filed papers in local courts in nine counties to acquire easements it will need to build the pipeline. The company filed those court papers two days before a two-year window closed.

TransCanada seeks a 50-foot-wide strip of land on which to build the pipeline. Landowners would continue to own the property; the pipeline would be constructed and operated below ground.

In a statement, company official Andrew Craig said TransCanada will continue negotiating settlement agreements with landowners during the court proceedings. The company estimates that it will need to acquire easements on 12 percent of the land the pipeline would eventually cross.

“Eminent domain is a last resort and our first priority is always to negotiate voluntary agreements with landowners. However, where needed, eminent domain allows necessary commodities like food, oil, natural gas and power to have the safe transportation corridors needed to get to where they are used,” Craig said. “We have made numerous offers to negotiate generous agreements with all landowners.”

But the legal wrangling is far from over. Attorneys representing the landowners who have tried to block construction of the pipeline filed suit last week challenging the constitutionality of a 2012 law that would allow Nebraska’s governor to give the project a green light.

Four of the seven state Supreme Court justices have ruled that law unconstitutional in a previous suit. The Supreme Court rules require five of the seven justices to overturn a law on constitutional grounds. The remaining three justices did not rule on its constitutionality and asked for another case in which landowners proved they had standing.

The new suit, filed Friday, involves landowners who can show proof that the pipeline would cross their land. The landowners said TransCanada’s use of eminent domain gives them standing to show how they would be damaged by the law they are challenging.

“The court will have to decide the issue that wasn’t decided on Jan. 9, which is, is the Nebraksa statute under which TransCanada proceeds unconstitutional?” said David Domina, an attorney for the landowners. “We think we have an enormously strong likelihood [of winning] on the merits.”

TransCanada estimates that about 90 landowners have yet to sign over easement rights. Domina said he didn’t trust the company’s estimates.

If the eminent domain proceedings continue, court hearings in the nine counties where TransCanada filed papers Tuesday will determine the value of the easements the company seeks, and the amount of compensation to which landowners would be entitled.

Construction of the pipeline is the top priority of new Senate Majority Leader Mitch McConnell, who brought a measure to the floor last week. The Senate continues to debate amendments to the bill Wednesday, with final passage expected next week.