DUBAI - Qatar National Bank (QNB), the Gulf's biggest bank by assets, on Wednesday started marketing U.S. dollar-denominated bonds with a seven-year maturity, a document showed.

QNB has hired Barclays, Credit Agricole, Mizuho, QNB Capital and Standard Chartered to arrange the potential deal, which would be of benchmark size - normally meaning upwards of $500 million.

QNB Finance is the issuer and Qatar National Bank is the guarantor for the debt sale, marketed with an initial price guidance of around 155 basis points over mid-swaps.

QNB's potential deal - expected to close later on Wednesday - follows a $600 million Formosa bond deal last month, as the bank taps different markets to diversify its funding. 

Another Gulf bank, Kuwait's Boubyan Bank, announced on Wednesday its plan to raise hard currency debt through bonds. 

Regional banks tend to cover their funding needs in debt markets in the first months of each year, but a rise in bond spreads over the past few weeks might hamper issuance from corporates in the region, fund managers said, with the new coronavirus outbreak adding uncertainty to market conditions.

(Reporting by Davide Barbuscia; Editing by Kevin Liffey and Louise Heavens) ((Davide.Barbuscia@thomsonreuters.com; +971522604297; Reuters Messaging: davide.barbuscia.reuters.com@reuters.net))