Lyttelton Port's board is unanimous in recommending shareholders accept a $3.95 per share takeover offer from the major shareholder, Christchurch City Council.
The directors have also agreed the port will pay a special dividend of 20 cents per share to existing shareholders to use up its imputation credits.
That means the offer values the port $424.4 million, or $4.15 per share.
Both Christchurch City Council, which owns nearly 80 percent of the port, and Port Otago, which owns nearly 15.5 percent, had already agreed to accept the offer before it was made public.
Once a bidder gains more than 90 percent of a company, it has the right to compulsorily purchase the remaining shares.
Independent valuer Northington Partners said the offered price is about 14 percent higher than the top end of its valuation range of $3.35 to $3.65 per share.
Northington Partners says it thinks the council needed to offer Port Otago a premium and that it may have determined the high price is more than compensated for by the strategic value gained by moving to 100 percent ownership.