DUBAI - Aldar Investment Properties, a unit of Abu Dhabi's largest developer Aldar Properties , launched a $500 million 10-year debut green Islamic bond, or sukuk, on Wednesday, according to a bank document seen by Reuters.

The company held investor calls on Tuesday ahead of a potential issue, the proceeds of which will be used to finance or invest in eligible projects under its Green Framework.

The sukuk was launched at a spread of 150 basis points over U.S. Treasuries, tightening from guidance released earlier in the day of 185 bps over Treasuries, as order books topped $2.2 billion.

HSBC and Standard Chartered Bank were mandated joint global coordinators, along with Abu Dhabi Commercial Bank, Abu Dhabi Islamic Bank, Dubai Islamic Bank, Emirates NBD Capital, First Abu Dhabi Bank and Mashreq as joint lead managers and joint bookrunners.

Earlier this month, a senior Aldar executive said the company would only tap debt markets opportunistically, and was in a comfortable liquidity position, with 6.1 billion dirhams ($1.66 billion) in free cash and 4.4 billion dirhams available in undrawn facilities.

There has been a pickup in Islamic debt issuance from Gulf credits recently as borrowers look to tap a broader investor base and meet demand for an under-supplied asset class.

($1 = 3.6717 UAE dirham)

(Reporting by Rachna Uppal; editing by Sharon Singleton and Jason Neely)