Brookfield (BN) has upped its bid for Reliance for the third time, to A$4.75 ($3.37) a share and a total of A$4.1 billion in the latest iteration, the Australian plumbing-supplies enterprise reported on Tuesday.

Brookfield's proposal follows earlier but rising offers, also unsolicited and non-binding, of A$4.15, A$4.25 and A$4.50 a share, a string that started in April, said Reliance, which has administrative headquarters in Melbourne.

The latest bid from private-equity house Brookfield constitutes a 31.6% premium to the company's last closing price of A$3.61 per share on Aug. 17, and a 43.2% premium to Reliance's six-month average price of A$3.32 per share up until Aug. 17, said Reliance, which also has an operational headquarters in Atlanta.

Reliance said it will enter into a four-week negotiation period with Brookfield, but will also enter a 30-day "go shop" span, during which it can solicit rival bids.