DUBAI - Aluminium Bahrain (Alba), owner of one of the world's largest aluminium smelters, is raising $1.5 billion in bank debt to refinance loans it obtained in 2016 to back its Line 6 expansion project, two sources familiar with the matter said.

The company has mandated three Bahrain-based banks – National Bank of Bahrain, Bank ABC and Gulf International Bank – to underwrite the facility, which is now being syndicated to the wider bank market, said the sources.

Alba – which declined to comment – completed $1.5 billion in financing in 2016, marking the largest corporate loan ever raised in Bahrain.

The three banks leading the debt raising did not respond to comment requests.

Alba's original loan, split into an $882 million conventional tranche and a $618 million sharia-compliant tranche, had a seven-year maturity and was coordinated by JPMorgan, National Bank of Bahrain and Gulf International Bank.

Alba's financial performance has recently been hurt by lower London Metal Exchange (LME) prices, U.S.-China trade tensions and a drop in aluminium demand in North America and Europe.

It posted a loss of 19.1 million Bahraini dinars ($50.69 million) in the first half of this year.

($1 = 0.3768 Bahraini dinars)

(Reporting by Davide Barbuscia; editing by Jason Neely) ((Davide.Barbuscia@thomsonreuters.com; +971522604297; Reuters Messaging: davide.barbuscia.reuters.com@reuters.net))