AMSTERDAM (Reuters) - MessageBird, one of Europe’s fastest-growing software companies, said on Wednesday it had agreed to buy email giant SparkPost for $600 million in a deal that will increase its sales by around 50% and expand its client base in the United States. MessageBird also announced one of the largest financing rounds for a European tech startup on record to pay for the deal, raising an additional $800 million from investors including Eurazeo, Tiger Global and Owl Rock. MessageBird, a cloud communications business sometimes compared to Twilio, helps corporations organise and manage communications with customers that may be switching between smart phone messaging apps, video conferencing tools, web chats, and voice calls at different times. SparkPost, the largest sender of business-to-customer emails, helps companies send and analyse their email communications. MessageBird CEO Robert Vis said the deal would give the company access to SparkPost’s U.S. customer base while SparkPost’s product would improve its offerings to customers in the rest of the world. “This will put a smile on the face of my sales team,” he said in a phone interview. The deal will increase the group’s combined sales to $500 million based on their most recent financial years, he said. In March, Reuters reported that MessageBird’s 2020 sales had passed $300 million after strong growth amid the coronavirus pandemic. To finance the deal, MessageBird added $800 million to a previous $200 million “series C” funding round in October 2020, valuing MessageBird at $3.4 billion, Vis said. The SparkPost transaction is expected to close this quarter, pending regulatory approval, the companies said. The acquisition will be the fourth in the past half-year for MessageBird, after it spent $100 million to buy France’s Hull.io, Britain’s Pusher, and 24sessions of the Netherlands. . MessageBird has said it would be ready for an IPO this year, but Vis said it had not decided whether to seek a listing, and hadn’t hired banks. Among MessageBird’s 15,000 customers are Uber, Domino’s, Telegram, Lufthansa, Heineken and SAP. SparkPost customers include the New York Times, Zillow, Adobe and Booking.com.