Key Points:

One of Great Barrier Island's two air carriers says its rival's latest tit-for-tat tactic is aimed at putting him out of business and ending nine years' competition that has kept fares down.

Keith McKenzie of Great Barrier Air says a High Court ruling has given its competitor, Great Barrier Airlines, control over the Auckland office telephone numbers used by his companies.

Great Barrier Airlines, which began the island run in 1983, has won an interim court injunction to stop the use of the Great Barrier Air name in advertising or promotion material.

Justice Helen Winkelmann agreed that the two names were so close that confusion was inevitable.

Pending the outcome of the case at trial, the judge ordered Great Barrier Air's telephone lines to be independently monitored to ensure that anyone seeking its rival's operation is directed to the correct business.

The two airlines have a history of court cases and attempts to thwart each other's business.

The latest injunction bid was prompted when Mr McKenzie created shell company Great Barrier Air to allow Great Barrier Xpress Mountain Air's advertisement to sit ahead of the Great Barrier Airlines' ad in the directories.

He said the advertising ploy was a countermeasure to Great Barrier Airlines forcing Yellow Pages to switch Great Barrier Xpress to its own telephone number. The parties dispute who has the right to use Great Barrier Xpress in advertisements.

Since December 21, all calls to the McKenzie companies' Auckland office lines are automatically diverted to a Telecom answering service, which asks whether the caller wants Great Barrier Airlines or Great Barrier Xpress Mountain Air.

When the Herald tried the Great Barrier Air 0800 number it was put through to Great Barrier Airlines even though it requested Great Barrier Air.

"The way it's been done is contrary to the intention of the court and clearly is aimed to try to put us out of business," said Mr McKenzie.

"It's like if you take a bus to do your normal shop at Pak 'N Save and the bus driver stops outside New World and says, 'Here's where you shop'."

Mr McKenzie said his company had about 35 per cent market share, though his rival says it is less.

Without his company's competition, he said, the public would face stiff hikes in fares for the half-hour flight to the island.

Nine years' competition had kept the price within a dollar of Great Barrier Airlines' 1998 schedule, despite a trebling in aviation fuel prices.

Mr McKenzie said he wanted an urgent hearing of the case because monitoring was losing the company considerable business at the busiest time of the year and was incurring charges of $1.97 for each call centre diversion.

Island tourism business operator Tony Bouzaid said guests did get confused by the Great Barrier Air listing. But he said the island's tourism benefited from healthy competition.

Island community board chairman Paul Downie said tourism operators gave information on both airlines.

"We are a small community and realise we are lucky to have two airlines."

Great Barrier Airlines' director, Mark Roberts, said the fact that calls were regularly coming through from the diversion service proved that people who wanted Great Barrier Airlines were being fooled into dialling the wrong number.

The number of diverted calls would enable the company to establish the amount of bookings lost before the monitoring service was in place.

Mr Roberts also said Telecom had agreed that in light of upcoming court cases neither company would use the Great Barrier Xpress directory listing.

WHO'S WHO

* Great Barrier Airlines: The first local airline, which has flown to the island since 1983.

* Great Barrier Air: The new name for its competitor, which has been operating for nine years.