Controversial Frank Kush was given a five-year contract to coach the Baltimore Colts today in hopes that he can turn around the sagging fortunes of that franchise.

Less than 24 hours after the Colts concluded their worst season ever (2-14) with a 23-21 victory over equally inept New England, Mike McCormack was fired with one year remaining on his coaching contract, reportedly worth $150,000 annually.

McCormack was told he was fired this morning after showing up at his office. He was seen leaving just before the press conference began and declined comment then.

Later, the Colts released the following statement from McCormack: "I was disappointed in the announcement, but at the same time it has been a season of disappointment and I fully understand the reason . . . I would have liked to have had another year to prove that we were not as bad as a 2-14 team . . . I will investigate all opportunities. My wife and I enjoy this area and would like to remain here."

Team owner Robert Irsay was conspicious by his absence at today's press conference, which was totally the Frank Kush Show. The eccentric owner was in Chicago (his business interests are in suburban Skokie, Ill.) and General Manager Dick Szymanski simply introduced Kush and walked away.

In McCormack's first year with the Colts, the team finished 7-9. With the drafting of Randy McMillan, the 225-pound fullback from Pittsburgh, to team with the previous No. 1 pick, Curtis Dickey, there was reason for optimism over this season.

After an opening victory at New England, however, the Colts lost 14 straight games before beating the Patriots Sunday before a crowd of 17,073 at Memorial Stadium, the smallest crowd in the NFL this season.

During the season there was constant turmoil between McCormack, 51, and quarterback Bert Jones and a flare-up between Jones and Dickey. Cornerback Derrick Hatchett also publicly criticized Defensive Coordinator Chuck Weber and, in a game at Philadelphia, Irsay took over the play-calling from the press box level.

Kush was high on the Colts' list of candidates before they hired McCormack, but at that time the former Arizona State coach was deeply involved in a legal suit stemming from an incident in which he allegedly slapped punter Kevin Rutledge. Kush was later found innocent of the charge, but lost his job and coached Hamilton of the Canadian Football League last season.

The NFL recently concluded an investigation to determine if Kush was suitable to coach in the league, according to a report in yesterday's Boston Globe. William Roemer, a former FBI agent from Arizona, conducted the investigation of Kush's alleged telephone conversations with Detroit gamblers in the late 1960s and early 1970s.

According to the Globe, an Internal Revenue Service affidavit alleged that 1,900 phone calls were made among Kush and convicted Detroit gamblers Donald Dawson and Howard Sobers, and that 60 calls were made to Kush, many in close proximity to Arizona State games. The affidavit also alleges Kush was paid in the form of heavy bets on rigged golf matches between him and Sobers. Kush was allowed to win those matches.

"I have no legal problems anymore in Arizona," Kush said today in response to questions about the NFL investigation. "The NFL has to approve all contracts and they approved mine this morning."

Kush said that he rejected offers from Purdue, Colorado and Pitt while at Arizona State and also added he "turned down the Eagles' job before they hired Dick Vermeil because I thought I'd spend the rest of my life at Arizona State."

"It was a jump ball for a while between McCormack and Kush," Assistant General Manager Ernie Accorsi said of the decision two years ago to hire McCormack, whose teams were 16-25-1 in his three years as head coach at Philadelphia. "We liked both of them, so now candidate A didn't work out, we went to candidate B."

Although there have been rumors for a week that Kush would replace either McCormack or Ron Erhardt at New England, Kush said he hadn't talked with anyone until Thursday, when Irsay called.

"Szymanski and I go back a long way, we played against each other in college, and I've known Ernie for a long time, too," Kush said. "But nobody talked to me officially before last Thursday. Since then, we've been working back and forth on the phone. My contract wasn't settled and signed until this morning."

Kush said there was a clause in his contract with Hamilton that either side could terminate the pact at any time. In his one season with the Tiger Cats, he took them from an 8-7 record to 11-4-1 before they lost in the playoffs.

"It was a great learning experience," Kush said of his season in Canada. "It was the first time I had worked with pros and I enjoyed it, but I couldn't afford to pass up this offer."

Kush has been called a tough, demanding coach. He set up a rigid training program in Hamilton that had many players complaining. He established a weight-lifting program they hadn't had before, but also brought beer into the locker room after games for the first time.

"I hate to overuse the word discipline, but that's what football is all about," he said. "You have to establish standards and have the players keep them.

"I've been tabbed by the media as a tough coach, but I don't think I'm any tougher than any other coach. I demand a lot of myself, I demand a lot of my coaches and I demand a lot of my players. If that's tough, then, yes, I am."

Kush said he wasn't familiar enough with the Colts' personnel or their staff to make any instant decisions about assistant coaches or trades.

When asked about Jones' future with the Colts, Kush said he never has met the quarterback and that Jones' future was not discussed when he talked about taking the job.

An associate of Jones said last night the quarterback will file a grievance soon against Irsay because, when the two met earlier this year and Jones sought to supplement his contract with the Colts, Irsay alledgedly said he had no contract.

Kush is the Colts' seventh coach in the 10 years Irsay has owned the team. Irsay purchased the franchise in July, 1972.

During his 22 years at Arizona State, Kush compiled one of the most impressive records in college football history. His career record of 176-54-1 ranked second only to Alabama's Bear Bryant among active NCAA coaches.