Abu Dhabi sovereign investor Mubadala is set to raise $1.5 billion from a dual-tranche bond sale that drew over $18 billion in demand, a bank document showed on Thursday.

The spreads were tightened by as much as 45 basis points (bps) from initial guidance to 105 bps over U.S. Treasuries (UST) for a 10-1/2-year tranche and 135 bps over UST for 30-year Formosa bonds, the document reviewed by Reuters showed.

Mubadala last tapped the debt markets in October with $1 billion 10-1/2-year Formosa bonds.

Abu Dhabi Commercial Bank, BNP Paribas, Citi, First Abu Dhabi Bank, JPMorgan and Standard Chartered are joint global coordinators on the dual-tranche bond sale.

Barclays, Credit Agricole, Emirates NBD Capital, Mizuho, Natixis and SMBC Nikko are also working on the deal.

The wealth fund, which manages $284 billion in assets, saw net debt increase by $4.5 billion in the year to end-2022, an investor presentation showed.

The fund has been actively investing this year. It will invest $500 million in U.S.-based broadband service provider Brightspeed, they said this month.

Mubadala and Asia's largest healthcare investment firm CBC Group last month led a $315 million investment in Chinese pharmaceutical firm Hasten Biopharmaceutic.

And in April, M42, a healthcare joint venture set up last month between Mubadala and Abu Dhabi artificial intelligence firm G42, said it was acquiring Bridgepoint Group's European dialysis clinic chain Diaverum. The deal could value the Sweden-based firm at about $2-$2.5 billion, a person familiar with the matter told Reuters.

(Reporting by Yousef Saba; Editing by David Goodman and Emelia Sithole-Matarise)