Billionaire Graeme Hart's $2.8 billion bid for Switzerland's SIG comes amid a heated and protracted battle for the packaging group.
SIG - the world's second-largest maker of drinks cartons - has been courted since the end of last year, when it told the Swiss bourse it had received
several non-binding approaches.
The firm rejected them all because it believed it had a more prosperous future as an independent company.
However, under increasing pressure from shareholders and later Swiss regulatory authorities, SIG opened its books to all comers, starting the auction into which Hart has just entered.
The Kiwi billionaire's main rival is a consortium made up of Norway's FERD, owner of packaging giant Elopak, and London private equity firm CVC. The consortium has bid 350 swiss francs a share ($411.85) - 20 francs less than the bid tabled by Hart.
FERD made its first approach to the firm in 1986. But its founder Johan Andresen said that this time he had decided to approach SIG shareholders directly because he had held talks with four different chairmen over the years, Bloomberg reported.
The combination of Elopak and SIG would create the second-largest force in drink and liquid food packaging, behind Tetra Laval, owner of the Tetra Pak brand.
Andresen has committed the firm to pursuing SIG, saying in September: "We will continue to follow this. We are strong in different areas: [SIG] are strong in Asia and we are strong in the US."
After Hart's bid SIG's shares rose 11 per cent to 398 francs, suggesting that investors anticipate a further offer.
Hart launched the bid for SIG on the same day as he disclosed it had agreed to buy International Paper's drinks packaging division for $725 million.
