The shares closed up 19% at 69c, the highest since February 27.
Tourism Holding (THL), subject to gaining 50% shareholder approval, will buy United Campervans and KEA Campers at the end of October in the deal comprised of cash, shares and debt.
Campervan numbers during the Rugby World Cup increased more than 5% to an estimated 11,500.
Listed THL, which picks up about 1000 campers from the acquisition, will during the next two years reduce its now 2500-strong fleet by almost 30% to 1800 to "rationalise" numbers.
While the acquisition equates to more than 50% of the Tourism Holdings market capitalisation, it is well below its banking debt covenant ratios, Craigs Investment Partners broker Peter McIntyre said.
"This is a big acquisition for THL.
"While it will come with some complications, if it is bedded in properly this could revitalise the business further," he said.
The $69.5 million acquisition is comprised of refinancing $50.9 million debt, the issue of 12 million THL shares at 61.9c per share and cash of $3.2 million. There is a deferred payment of up to $8 million based on vehicle selling prices meeting expectations.
THL chairman Keith Smith forecast that earnings before interest and tax in the forthcoming year to June 2013, were expected to rise from $16.3 million to $19.3 million, and in the following financial year, to June 2014, operating earnings were forecast to rise to $28.8 million.
After-tax earnings per share were expected to rise from 4.6c to 6.1c.
Mr Smith said the acquisitions would optimise THL's highly-competitive international sales and service infrastructure and create a strong advocate for New Zealand tourism in the high-value European and UK markets.
Mr McIntyre said it was positive to see consolidation in the New Zealand rental sector, but cautioned that it would be a large new operation, and it would still be reactive to currency movements and changes to European and Asian tourism trends.
Mr Smith said debt ratios were forecast to fall from 50% after the merger to 42% in the first year and 39% in the second year, as a planned fleet reduction programme progressed.
For its last financial year to June, THL posted an after-tax profit of $4.3 million, a turnaround from the previous year's $27.3 million loss - which had included a non-cash goodwill write-down of $26.1 million.
That result was driven by tight control of costs, operational improvements, the first full-year input from its US motorhome business Road Bear, and a surge in motorhome rental activity during the 2011 Rugby World Cup.
