About a third of the value of the Paramount Citrus contract will go to Fruit Handling Systems, a Hastings company 50 per cent owned by Compac.
Ian Fulton, Compac's chief executive, said the firm was "over the moon" that it had secured the deal, which had been two years in the making.
The company would employ eight new fulltime staff - as well as a number of part-timers - specifically to work on Paramount's order, he said.
Machinery required for the project would fill 40 shipping containers, which would leave Compac's Onehunga factory at the rate of two a week for the next five to six months.
The installation, to be done by a team of project managers and other staff which would travel to California, was expected to be completed by September next year.
Compac's sales and marketing director, Dave Buys, said the company's success in winning the contract was the result of the firm being the best-value provider involved in the tender process.
"We were able to show that over the life of the solution, our technology would not only give greater performance but have a lower cost of ownership," he said.
Fulton said that while the deal was a great outcome for the firm, the New Zealand dollar's strength against the greenback - it was trading above US83c late yesterday - eroded margins.
"When we first started discussions [with Paramount Citrus] the exchange rate was at US75c and then during the discussions it bobbed up to US87c - it has a serious impact on us," he said.
Compac has received assistance from both the Ministry of Science and Innovation (MSI) and New Zealand Trade and Enterprise.
Since 1999 it has received more than $4.25 million from MSI - formerly known as the Foundation for Research, Science and Technology.
Fulton said Compac's equipment could be found all over the world, from France and Morocco to China, South Korea and Canada.
Privately-owned Compac was founded in 1984 by Hamish Kennedy, who still holds a 75 per cent stake in the business.
PARAMOUNT CITRUS
* Founded in 1950.
* Based in Delano, California, with plants also in Visalia, California, and Mexico.
* The largest grower, shipper and marketer of fresh citrus in the United States.
* Processes up to 10 million cartons (200,000 tonnes) of fruit annually, which is shipped throughout North America and the Pacific Rim.
* Is the largest clementine mandarin grower in the United States.