The Minnesota Vikings have reached agreement with the Houston Oilers on a trade to enable the Vikings to draft University of Miami quarterback Bernie Kosar.

The Vikings will get the Oilers' first-round choice in the 1985 NFL draft (the second selection overall) in exchange for Minnesota's first- and second-round selections. Minnesota is slated to choose third in the first round.

The Buffalo Bills already have signed Virginia Tech defensive lineman Bruce Smith with the league's first overall pick.

Kosar, who has one year of college eligibility left because he was redshirted as a freshman, has not "officially" declared to enter the draft, a strategy that may allow him to sign with the Cleveland Browns, the club which he has said he prefers.

According to NFL spokesman Joe Browne, Kosar has not formally sent a letter to the NFL declaring his intention to leave college early. "If we do not get a letter by April 15, Bernie Kosar would not be eligible for the April 30 draft," Browne said. "Then if he lets us know at a later date he does want to play in 1985, we would hold a supplemental draft with Kosar and other players who fit into that category."

Cleveland moved into position to draft Kosar in the supplemental draft by giving Buffalo "future considerations" for the No. 1 selection in that draft . . .

The St. Louis Globe-Democrat reported that middle linebacker E.J. Junior has signed a four-year contract with the St. Louis Cardinals . . .

The USFL's Portland Breakers waived wide receiver Lenny Willis and traded a future draft choice to the Baltimore Stars for defensive end Mike McInnis. Willis, a native of Washington, D.C., graduated from Theodore Roosevelt High and starred at Ohio State.