The NCAA today barred the Illinois basketball team from postseason play for the 1990-91 season as the result of a 16-month investigation into the Illini's recruiting practices.

The NCAA, at a news conference in Overland Park, Kan., said the men's basketball program was placed on probation for three years beginning this season and will have its recruiting restricted for the next two years.The school will be banned from off-campus basketball recruiting and from paying for visits by recruits to its campus the first year, the NCAA said.

The school also will be limited to awarding just two basketball scholarships in each of the first two seasons of the probation, but television coverage will not be restricted.

The NCAA said "significant violations occurred." But it said evidence did not substantiate the most serious allegations - that Illinois offered large sums of cash and cars to lure key recruits to campus.

"The Committee on Infractions has concurred with our judgment that the evidence doesn't support the main allegations," Illinois Chancellor Morton Weir said in a statement this morning. "We expected that, but it is nonetheless a relief to be at the end of that road.

"We disagree with several of the committee's findings, and some of the sanctions are harsher than we expected," he added.

The university's recruitment in 1989 of prep star Deon Thomas touched off the investigation. The university said its own probe revealed some minor infractions.

The NCAA also found the school guilty of improper use of complimentary tickets by former players; the setting aside of NCAA tournament tickets for purchase by high school coaches; preferential treatment given to three players last year when the players were not required to completely fill out auto loan applications from a Decatur bank; and illegal recruiting contacts by recruiter Jimmy Collins.

Prior to its findings, the NCAA accused Collins of using improper inducements in an effort to sign two high school basketball stars.

The NCAA had charged that in 1987, LaPhonso Ellis of East St. Louis was offered $5,000 to sign and $5,000 a year to play for Illinois as well as the use of a car.

The agency said Thomas was offered $80,000 and a Chevrolet Blazer to join the Illini.

Collins denied the accusations, saying: "I didn't offer anybody any money."

Athletic Director John Mackovic said in a statement this morning, "We are pleased that Deon Thomas' eligibility to play basketball at Illinois was restored and that the committee found that Jimmy Collins had not engaged in unethical conduct."

Mackovic said he was disappointed that his own investigation turned up rule violations and he said the management of the basketball program will be strengthened.

Illinois coach Lou Henson, who took his team to the Final Four two years ago, is preparing for his 16th season. This was the first time his basketball program had been investigated by the NCAA.

Reports that Illinois' signing of Thomas had raised questions about basketball recruiting were confirmed in July 1989 when the university announced that the NCAA had initiated a preliminary inquiry.

Illinois apparently was turned in by rival recruiter Bruce Pearl of Iowa. He secretly recorded a telephone conversation with Thomas in which the 6-foot-9 Chicago Simeon star appeared to confirm that Illinois offered him cash and a car to sign.

Thomas later contended that there were no improper inducements and that he merely agreed with Pearl's accusations to get rid of him. He said the only improper offers were from Iowa.

But, there was no immediate explanation for Ellis' statements to NCAA investigators that Illinois made a similar cash-and-car offer in its unsuccessful attempt to recruit him while he was at East St. Louis Lincoln.

The NCAA preliminary inquiry turned into a full investigation, and the agency accused Illinois in February 1990 of 11 violations of its recruiting rules.