Auckland International Airport Ltd is raising $126 million through a share offer.
The money will be used to repay some of the debt that was acquired to buy a 24% stake in Northland Queensland Airports earlier in January.
Eligible shareholders can buy one new share for every 16 currently held at a price of $1.65 each - a 14% discount on the company's last traded share price.
The offer is fully underwritten by First NZ Capital and Credit Suisse in Australia.
In an unusual move, institutional shareholders, which own about two thirds of the company, have until Thursday afternoon to decide whether they will buy more shares. Retail investors have until 18 February.
Meanwhile, Auckland International Airport Ltd says its earnings rose by almost 5% to $54 million in the last six months of 2009.
Revenues were flat at $183 million, while passenger numbers increased more than 2% over the period.
Councils vote to retain stakes
Auckland City Council is to spend more than $15 million to keep up its stake in Auckland International Airport Limited.
At present, the council has a stake of 12.71% in the company. Councillors voted to maintain it at that level at an extraordinary meeting on Wednesday.
Auckland City mayor John Banks says the council is borrowing the money to take up the shares that otherwise would have eroded.
Mr Banks says the airport company has not been performing well, but it is a strategic asset.
Manukau City Council has also voted to keep its 10% stake at a cost of nearly $13 million.
Shares held by the councils will be transferred to the new Auckland super-council.