Fund manager Perpetual has rejected a sweetened takeover bid from Regal Partners and a private equity firm, citing the revised offer as being too low.

The rejection comes amid market debate about Perpetual’s separate plan to merge with rival Pendal, as details emerged on Thursday that Perpetual had sought to delay that deal.

With the battle over the future of Perpetual continuing to heat up, Regal said it was “deeply disappointed” to have been rebuffed a second time.

Perpetual, which is more than 130 years old, has in the past week emerged as a takeover target of Sydney hedge fund Regal, led by Phil King. On Thursday, Perpetual told the ASX that a consortium comprising Regal and private equity firm BPEA had lifted its cash bid for it to $33 a share, after last week’s opening bid of $30 a share.

Perpetual’s board has knocked back the revised bid, which it said “materially” undervalued the company, and advised shareholders to take no action.

“Perpetual’s Board has considered a number of factors, including value, high conditionality, transaction and execution risks, in determining that the Consortium’s Revised Indicative Proposal is not in the best interests of its shareholders and has therefore rejected the offer,” Perpetual’s board said.

Even so, Perpetual’s statement did not repeat its comment from last week that it was committed to carrying out its acquisition of Pendal.

Pendal, formerly known as BT Investment Management, revealed on Thursday that Perpetual had sought the delay to the merger, adding that it still wanted to proceed with court hearings to progress the deal this week.

Some analysts have been sceptical of Perpetual’s plan to merge with Pendal, arguing last week that Perpetual should engage with Regal to seek a higher price for shareholders. But so far, Pereptual’s board has opted not to engage with the suitor.