New Zealand accounting software giant Xero agreed to buy New York payments provider Melio for $2.5 billion, the companies said on Wednesday, accelerating the Kiwi firm's push into the U.S. with the country's biggest outbound deal in over a decade.

Xero Ltd., a cloud-based accounting software firm, agreed to buy Melio Payments Inc. for $2.5 billion as the New Zealand company pushes deeper into the US market with its biggest-ever acquisition.

Xero Ltd (ASX:XRO), the New Zealand-based cloud accounting software provider, announced a $2.5 billion acquisition of U.S.-based payments processor Melio Ltd. The binding agreement includes both cash and equity,