Adil Taqi never wanted to be reliant only on banks.

As chief financial officer of Damac Properties, a Dubai-based real estate developer with annual revenues of $2 billion, one of his priorities since taking the role in 2013 has been to broaden the company's investor base. One step in 2014 was to issue a sukuk - an Islamic finance instrument that works broadly like a bond - to raise $650 million.