(Adds detail, background) April 14 (Reuters) - Australian buy-now-pay-later (BNPL) firm Zip Co said on Wednesday it will raise A$400 million ($307.48 million) through senior unsecured convertible notes to fund its growth and expansion plans. On Tuesday, the BNPL firm reported a record quarterly earnings and unveiled plans to expand into Canada and Southeast Asia. “The additional capital from this offering will support the active pursuit of both core and international growth opportunities,” Chief Operating Officer Peter Gray said in a statement. BNPL firms, which allow users to pay for their purchases over several installments, have seen a boom in transaction volumes and active customers as the pandemic changed consumer behaviour drastically, moving more towards the online space. Zip, which saw transactions volume more than double in the March quarter, picked up a strategic stake in Philippine firm TendoPay and made a soft launch in Canada during the quarter in a bid to compete better with its larger rivals like Afterpay . The senior notes are expected to be listed on the Singapore exchange, Zip added.