Canadian dairy firm Saputo has increased its stake in Warrnambool Cheese & Butter Factory Holdings Ltd to almost 18 per cent.
Saputo and Australian dairy group Murray Goulburn Co-operative are the two companies still battling for control of WCB, after Bega Cheese recently allowed its bid to lapse.
Saputo said on Tuesday it now holds 17.92 per cent per cent of WCB shares.
However, 13.35 per cent of those shares remain subject to withdrawal rights, with investors who accepted Saputo's offer before December 17 allowed to withdraw their acceptance before January 3.
Murray Goulburn holds a 17 per cent stake in WCB.
Saputo is offering $9.00 per WCB share but under changes to its bid made on December 17, that price will increase to as much as $9.60 as its stake in the company increases.
Saputo's current bid is final.
Murray Goulburn's bid of $9.50 is conditional upon it obtaining more than 50 per cent of Warrnambool shares.
Shares in WCB were steady at $9.25 at 1412 AEDT.