for millionaire businessman Mr. Michael DeGroote, it was alleged in Supreme Court yesterday.

Mrs. MacMillan, heiress to the American Cargill grain fortune, wants out of a $8.5-million deal she signed in 1990 to sell Perot's Island to Mr. DeGroote.

Mr. DeGroote, the millionaire former owner of Canadian transportation and waste giant Laidlaw, has gone to court to seal his claim to the island retreat in Riddell's Bay.

Among the pleadings in Mrs. MacMillan's counter-claim is that her realtor, The Bank of Butterfield Executor and Trustee Co. Ltd. (Betco), promoted the interests of Mr. DeGroote above her own.

Yesterday, Puisne Judge the Hon. Mr. Justice Ground agreed to amend the pleadings to add a specific allegation from Mrs. MacMillan's lawyer, Mr.

Julian Hall MP.

Mr. Hall alleged that in August of 1990 Ms Jonelle White of Betco provided Mr.

DeGroote with details of proposed construction and renovation works on Perot's Island.

"In so doing, the said Jonelle White acted without the instructions of the defendant and/or without her permission or consent, and further breached an assurance given by her...that she would not divulge the said list of works to the plaintiff,'' Mr. Hall said.

Mr. Gordon Harris of engineers and designers Woodbourne Associates Ltd.

testified he prepared estimates for $3.5 million in renovations originally proposed for Perot's Island. That "grand scheme'' was later scaled down, he said.

In August of 1990, Mr. Harris said Ms White requested a list of works to be completed at Perot's Island.

"I had specific reservations about giving her a list of works,'' but agreed to do so when Ms White "assured me it would go no further than her'', Mr.

Harris said.

When Mr. DeGroote made his first offer for the island on August 14, 1990 through his realtor Cooper Associates, reference was made to the Woodbourne Associates list.

Mr. Harris testified he did not learn the list was disclosed until November 15, when he received a letter from lawyer Mr. Jerome Dill of Appleby, Spurling and Kempe.

"I must first of all advise that I am annoyed at Jonelle White for ever having shown the list...to the potential purchaser,'' Mr. Harris wrote back. He said he only hoped the disclosure would "not have an adverse effect upon the sale of the property''.

Betco lawyer Mr. Mark Diel of argued Mr. Hall should not be permitted to amend his pleadings in the fifth week of the case. Betco, a third party in the action, has yet to present its case.