"I will be as disciplined on this bid as I've been on every other endeavour," chief executive Marius Kloppers told a conference call with reporters yesterday.
"The shareholders own the company and it's my job to create more value for them, not to do any one thing at any cost."
Analyst Paul Galloway at Bernstein Research in London said there was no reason for BHP to increase its bid in the near term.
"At the moment if BHP raised the bid they would be just bidding against themselves. So really the next move is from (Potash CEO) Bill Doyle, who claims that he's got an alternative. I think BHP will be waiting to see what that alternative actually is."
Potash Corp shares in New York, which have gained 31 percent since BHP unveiled its bid on hopes of a sweetener, fell 1.5 per cent to $146.87 by yesterday afternoon, compared with a 0.5 per cent fall in the Dow Jones industrial average.
The shares are still about 13 per cent above BHP's offer.
BHP posted its best half-year profit in two years, and its hefty balance sheet and net annual cash flows of $17.9bn confirmed the miner has the financial muscle to raise its $130-per-share offer for the top global fertiliser maker.
Net debt for the group, which has lined up $45bn in loans for the Potash deal, fell 58 per cent from the end of last year to $3.3bn, with net gearing down to a mere 6 per cent.