Bermuda-based Canadian millionaire Mr. Michael DeGroote will reliqnuish the chairmanship of Atlanta-based Republic Waste Industries, Inc. as part of a capital injection in the company by American billionaire Mr. Wayne Huizenga.

Under an agreement announced yesterday, Mr. DeGroote, currently chairman, president and CEO of solid waste services company Republic, will buy 1.5 million new shares for $6.75 million and warrants to purchase an additional 3 million shares.

Mr. DeGroote, who now owns 44 percent of the company through his Bermuda-based holding company MGD Holdings, will have invested an additional $21.9 million into Republic if he exercises all his warrants, the company said.

Mr. DeGroote, who acquired Republic in 1991 and has resided in Bermuda since 1990 after he sold Canadian waste management company Laidlaw, will become vice-chairman of the company.

The agreement will see Mr. Huizenga become Republic's chairman and CEO position later this year.

In seven years Mr. Huizenga took Blockbuster Entertainment, which merged with Viacom Inc. last year, from a company with an estimated market value of $32 million to about $8.4 billion.

Mr. Huizenga and associates will invest $27 million in Republic for 6 million new shares and warrants to purchase 12 million more shares.

If they exercise all their warrants, their total investment in Republic will be $91.5 million.

The company also announced Republic has entered into a merger agreement with Mr. Harris Hudson, Mr. Huizenga's brother-in-law, to acquire all the outstanding capital stock of Hudson Management Corp. and an affiliated company.

Mr. Hudson will become president of Republic.

"I am confident that the new energies, capital and businesses being brought into the company by the Huizenga and Hudson Management transactions will set Republic on an unparalleled growth pattern in the solid waste industry,'' said Mr. DeGroote.

Hudson Management provides solid waste collection services for over 140,000 residential, commercial and industrial customers in Florida.

Hudson Management's 1995 revenue is expected to exceed $50 million, about the same as Republic's present annualised revenue.

The transactions are subject to stockholder and regulatory approval in third quarter 1995.

Republic's stock soared $3.875 to $7.75 on volume of 4.9 million shares Nasdaq, where it was among the most active issues.

"Anytime someone puts up serious money like that, the shares are going to go up,'' a trader said.

The agreements would reduce the stake of Republic's current public shareholders to about 25 percent from 56 percent, said company spokesman Mr.

Courtland Peddy.

Mr. Huizenga was a co-founder of WMX Technologies Inc. and is the head of Blockbuster Entertainment, the world's largest video rental and music retailing company, which merged with Viacom Inc. in September, 1994.

Republic said it would use proceeds from the transactions to pay off all the debt of Republic and Hudson Management and result in the combined company having several million dollars in cash.