SINGAPORE - Singapore's biggest initial public offering (IPO) in six years opened little changed from its offer price.

Units of fibre optic cable owner NetLink NBN Trust opened at 81.5 Singapore cents, just above its offer price of 81 Singapore cents a unit when trading commenced at 3pm on Wednesday (July 19).

Given NetLink's large offer size of S$2.3 billion, pricing for a pop would have been difficult, since it would take tremendous demand to outstrip the large supply of shares.

The IPO was two times subscribed with S$4.7 billion worth of subscriptions received.

The offer comprised a public offer of 185 million units, and an international placement tranche of 2.7 billion units.

About half the public tranche went to small investors who applied for fewer than 100,000 shares with success rate of at least seven in 10.

NetLink NBN Trust's IPO is the biggest here since Hutchison Port Holdings Trust raised US$5.5 billion (S$7.6 billion) in 2011.

Based on a price of 81 Singapore cents per unit, NetLink's IPO investors can expect an annualised dividend yield of 5.43 per cent for the period to March 31 next year, and a 5.73 per cent yield for the year after that.