Investment Corporation of Dubai (ICD), the state-owned fund which holds stakes in some of the emirate's top companies, has tightened price guidance ahead of its debut bond and sukuk issue later on Wednesday, a document from lead arrangers said.

Revised guidance earmarks the sukuk with a six year lifespan to price in the range of 155-165 basis points over midswaps, while the conventional bond offering of 10 years duration is due to come in the range of 200-210 bps over the same benchmark, the document said.

This is inside previous guidance for the Islamic bond, which was given on Tuesday as in the area of 175 bps over midswaps, and at the tight end of the conventional offering's existing guidance of in the area between 200 and low-200s over the same benchmark.

Investor orders worth around $2.5 billion have been placed for the combined offering, the latest document said, up from the around $2 billion figure given by lead arrangers earlier on Wednesday.

The transaction comes three weeks after the Dubai government completed a $750 million sukuk issue, which received orders from investors worth more than three times the amount sold.

ICD will use the money it raises from the bond sale for general business purposes, according to the prospectus for the offering seen by Reuters last week.

The fund has holdings in some of the emirate's highest-profile brands, including Emirates airline, Emaar Properties and Emirates NBD.

The deal is being arranged by Citigroup, Dubai Islamic Bank, Emirates NBD, HSBC and Standard Chartered.-Reuters