A real estate agent who tampered with a sale and purchase agreement to increase her stake in a commission split has been reprimanded by an industry authority.

Valma Olliver of MH Realty Limited in Whangamata, was found to have engaged in unsatisfactory conduct by the Real Estate Agents Authority in a decision released today.

Olliver has been fined $5000 and ordered to apologise to the complainant for her actions.

The complaints assessment committee said Oliver inserted a clause in the sale and purchase agreement entitling her firm to 40 per cent of the commission on the property when she had no right to do so.

"She was well aware that this higher commission split had been rejected by the sole agent. There is no evidence that she alerted the listing agency to the insertion of this new clause," the committee said.

She had earlier tried to negotiate a 60/40 commission split on the property because she had a prospective buyer, but this was rejected in favour of an 80/20 split by the listing agency.

"Olliver collected the sale and purchase agreement (from the listing agent), and discussed its terms with her clients. Alterations were made to the sale and purchase agreement, which was returned to the listing agent."

Olliver said the clause was inserted to protect her agency's position in relation to the commission, but the committee said she knew the commission arrangement and therefore had no commission position to protect.

"The new clause was inserted in the sale and purchase agreement entirely out of self-interest, at a time when she knew the high commission split had been firmly rejected."

"The committee considers that had the vendor been a less knowledgeable person there was a real risk he would have been innocently involved in a commission dispute, as a direct result of Mrs Olliver's actions."

The authority said:

* Olliver put the vendor at risk of paying two commissions.

* Olliver must take responsibility for the inseration of the clause in the sale and purchase agreement, whether or not her office manager assisted in the preparation of the agreement.

* Olliver is an experienced agent, and she should have recognised that it was not good agency practice to undertake this sort of activity, the committee said.

* The complainant said Olliver spoke to the vendor to get him to pay the 40 per cent commission direct to her firm. Olliver has not responded to the allegation.

* Despite being told by the vendor that a sole agency existed, Olliver questioned the vendor about the price he wanted to achieve. She should have gone straight to the listing agent, without attempting to obtain any further information from the vendor, the committee said.