DuluxGroup appears to be having trouble convincing shareholders in takeover target Alesco to accept its $188.4 million offer for the company.

The paint manufacturer has managed to increase its stake in Alesco by just one million shares in recent weeks following its takeover bid for the garage doors maker.

In a statement on Wednesday, Dulux said it had increased its holding in Alesco to 19.76 million shares from 18.8 million since May 29.

Alesco had asked shareholders to take no action over the offer and its board last week rejected the bid.

DuluxGroup had offered $2 per Alesco share, but Alesco said an independent expert had valued the company at between $2.23 and $2.52 a share.

While DuluxGroup has extended its offer to July 20, it has far refused to increase its offer and has questioned the valuation basis of the independent expert.

A broker, who did not wish to be named, said Alesco shareholders seemed willing to follow the company’s advice and hold off accepting the takeover offer.

He also doubted a fresh offer from Dulux would be forthcoming, leaving both companies locked in a standoff.

“DuluxGroup have only just come out and said they won’t be increasing the bid so they can’t, only days later, come out and say they will increase the bid,” he said.

“And only last week Alesco rejected the bid so again they would look silly if only a week later they accepted the bid without any changes.

“I know they (DuluxGroup) extended the offer yesterday but I don’t know if they’re going to be successful at getting more acceptances unless they get support from the Alesco board.”

Alesco shares closed down one cent at $2.01, while Dulux finished one cent higher at $3.00.