The company's board had reviewed the applications received by the initial closing date of last Friday and, while applications were continuing to arrive, it was unlikely the offer would meet the threshold without an extension, chairman Rick Ramsay said.
The decision to extend until October 12 was based on continuing discussions with a "potential strategic and several institutional investors".
"We were unable to conclude these discussions before the IPO closure ... and the extension will give us time to potentially reach a positive conclusion," Mr Ramsay said.
The board recognised the uncertainty in global financial markets, particularly in equities. The new financial advisers regime also appeared to be limiting brokers' ability to make recommendations to their clients.
ACC, a pre-IPO investor in Energy Mad, had subscribed for a "significant" number of shares under the offer, and there had also been pleasing support from other institutional investors, he said.
The IPO would help provide the company with the capital it needed to secure and deliver on the market opportunities it was developing in the United States and Europe. It would also allow it to accelerate the introduction of the next generation of Ecobulb products.
Globally, Ecobulbs were saving enough electricity to power almost 25% of New Zealand for a year, and saving about $2.8 billion worth of electricity.
