BEND, Ore. -- When Nike co-founder Phil Knight pledged $100 million University of Oregon athletics last month, it seemed there was nothing left to stop plans for a new basketball arena.

But there is still the matter of the dental office, the 7-Eleven and a vacant building that used to house a Domino's Pizza. The three privately owned properties all sit on the site intended to house the new arena.

On Friday in Bend, the university will ask the state Board of Higher Education to allow the use of eminent domain for all three parcels, if necessary.

Eminent domain allows governments to buy private property for public purposes. In this case, the state would file a lawsuit claiming the properties on behalf of the university, and a court would determine how much the owners should be paid.

Melinda Grier, UO general counsel, told The Register-Guard newspaper of Eugene that the university still hopes to reach voluntary agreements with the property owners. But, she added, the university hopes to begin arena construction next year and needs assurance that the properties will be part of the site.

The university recently purchased a fourth property, a former gas station between the vacant building and the 7-Eleven store, for $570,000 from Eugene investor Peter Kryl.

The properties all are adjacent to the former Williams' Bakery site, which the UO purchased in 2005 for $25 million. The entire half block is expected to be developed as a new arena to replace McArthur Court.

Grier said she hopes a sale can be negotiated relatively soon with the two properties that have clear titles -- the 7-Eleven and the dental office.

There are a number of outstanding liens against the vacant business property, owned by Eugene resident Adesina Adeniji. Adeniji said in June that he and the UO had exchanged offers but could not agree on a price. He said he has been unable to find a tenant for the property because of doubts over its future as part of the arena site.

When the UO got permission to buy the bakery, the state sold $27.5 million in bonds to finance the deal. After paying for the bakery and the Kryl property, the UO has almost $2 million remaining to by the three remaining properties.

The university on Friday will ask the board to approve a "resolution of necessity," the first step in eminent domain. The resolution sets out the need for the properties but does not set any deadline for reaching a voluntary sale agreement or state how soon an eminent domain action would begin.

One complication could be Ballot Measure 39, which was approved by voters last November. It bars the state from condemning private property if it intends to transfer it to a private developer.

Although the land for the arena most likely would be owned by the UO, the arena itself might not. The university is considering a plan through which the UO Foundation would form a private, nonprofit corporation to build the arena.