The South Island's Ngai Tahu tribe has launched a takeover offer for the 18 per cent of tourism company Shotover Jet it does not own.

Shotover directors yesterday issued a "don't sell" notice to shareholders pending their commissioning of an independent appraisal of Ngai Tahu Holdings' 60c-a-share offer.

The company's shares were trading at 50c before the announcement, and closed at 60c on light trading.

Under the offer from Ngai Tahu, existing shareholders would keep a 1.25c per share dividend the company declared this month.

Shotover Jet runs jetboat businesses on the Shotover, Dart, Kawarau and Waikato rivers, and owns the Rainbow Springs and Farm, in Rotorua, and a Fiji jetboat business.

This month it reported a net profit of $4 million for the year to June 30 and said while its bottom-line result was down 10 per cent, operating profit before tax and unusual items increased 67 per cent to $3.6 million.

The company said it was hit by a downturn in tourists late last year, after the US terror attacks, but confidence had returned from January.

It has planned for growth-related capital expenditure over the next 12 months and will evaluate new investment opportunities "as they arise".

Ngai Tahu, through its holding company, has invested heavily in the tourism sector since receiving a $170 million treaty settlement in 1998.

As well as its 82.2 per cent stake in Shotover Jet, the tribe has a 43.5 per cent stake in Whale Watch Kaikoura and a 2.7 per cent stake in the country's largest tourism operator, Tourism Holdings.

Ngai Tahu subsidiary Ngai Tahu Tourism is the only substantial shareholder on the Shotover share registry - none of the 1300 other shareholders owns more than 0.69 per cent of the company.

Ngai Tahu's latest buy-up bid is lower than its past buy-ins. In 1999 it paid $1.05 a share for 41.3 per cent of the company. It added to its stake in 2000 and last year, paying 72c and 99.3c a share respectively.