"The contracting out proposal was not pursued as a strategy until recently, as a result of the threat of ongoing industrial action, the increasing competitive pressure on the company, and the inability to conclude an agreement with the union," she said in emailed answers to questions.
The emergence of the document highlights the bitter dispute between the port led by chief executive Tony Gibson and MUNZ that has been punctuated by strikes and lockouts. When shipping line Maersk and Fonterra Cooperative Group moved $47 million of custom to Tauranga they both blamed the labour dispute.
"Tauranga has a very good model," Gibson said.
Ports of Auckland spends $55 on labour for every container while Tauranga is estimated to spend $10 less - which if Auckland could match would see them save $6 million each year, the 'leaked' document says.
Container volumes at Auckland rose by 3 per cent, or 27,015, to 894,383 twenty-foot equivalent units, making it the country's biggest container port ahead of Tauranga, which handled 590,506 TEUs in its latest year.
Ports of Auckland and MUNZ have been engaged in 11 months of talks without resolution.
Garry Parsloe, the Maritime Union president, says that the union bowed to the port's demand for more flexible hours during six hours of talks yesterday but failed to clinch an agreement.
"We gave an undertaking to extend the shift as required," Parsloe said. Gibson "said that's great but it's not enough".
The introduction of flexible rosters would increase productivity, according to the port, while MUNZ says it would result in a loss of guaranteed hours and income for its members.
Putting stevedore services in the hands of competing contractors has contributed to Tauranga's superior productivity, according to a recent Ministry of Transport report.
Crane rates at Auckland averaged 25.1 containers an hour in 2010, while Tauranga exceeded that with 34.8, the report on container productivity said.
Shares of Port of Tauranga fell 0.5 per cent to $10.15 on the NZX today and reached a record-high close of $10.20 on January 5.