(Corrects first paragraph to say Thursday, not Friday)

RABAT, April 16 (Reuters) - Morocco's phosphates and fertilizer giant OCP raised $1.5 billion through its first international hybrid bond, becoming the first African group to issue a U.S. dollar-denominated hybrid on global markets, an OCP document showed on Thursday.

The transaction also re-opened MENA public primary bond markets after a hiatus of more than a month amid heightened volatility linked to the Iran conflict.

OCP's inaugural dollar hybrid was split into two tranches for April 2031 with a 6.74% coupon, and another for April 2036 with a 7.37% coupon, according to the OCP document that contains details on the issue and the context.

The bonds were arranged by BNP Paribas, Citi and JPMorgan.

Demand was strong despite geopolitical uncertainty, with the order book peaking at just under $7 billion, equivalent to 4.6 times oversubscription, prompting OCP to upsize the transaction, the document showed.

A total of 176 investors from 23 countries participated, it said.

The issuance comes amid tightening global fertiliser markets driven by supply constraints following tensions linked to the Iran conflict and China's export restrictions.

The OCP document, whose authenticity was confirmed by a senior company source, said disruptions to sulphur supply -- a key fertiliser ingredient -- following the closure of the Strait of Hormuz have pushed Middle East sulphur prices about 35% higher in April compared with pre-conflict levels.

State-owned OCP has secured enough sulphur inventory to cover operational needs through at least end-June, with diversified sourcing options including Kazakhstan, Canada, Europe, the Gulf of Mexico and the Red Sea, according to the document.

OCP, a phosphate-based fertilizer market mover, has upped its production capacity to 16 million metric tons in 2025 from 3 million metric tons in 2008.

To mitigate higher input costs, OCP has increased production of triple superphosphate (TSP), which requires less sulphur and no ammonia compared with diammonium phosphate (DAP), the document said.

TSP accounted for around 30% of volumes in 2025, with a target of more than 50% in 2026, according to OCP.

Earlier this month, OCP said it was bringing forward to the second quarter maintenance works slated for the third and fourth quarters, which would result in a 30% production cut.

(Reporting by Ahmed El Jechtimi; Editing by Janane Venkatraman)

By Ahmed Eljechtimi