Japanese e-commerce giant Rakuten has agreed to buy US eBook company OverDrive for about $410m (£275m, €380m), said managing executive officer Takahito Aiki.
Rakuten will turn Ohio-based OverDrive into a wholly owned unit, the Nikkei newspaper reported.
Shares in Rakuten have surged some 27% so far this year in Tokyo trade. By comparison, the benchmark Nikkei 225 share average has gained some 12%.
Earlier in the week, the online retailer said it had begun accepting payments in virtual currency bitcoin in the US. Rakuten sites in Germany and Austria will follow suit, the company said.
"The integration with Bitnet's platform will make Rakuten one of the largest ecommerce companies in the world to begin accepting bitcoin.
"In addition to offering consumers enhanced security, privacy, and convenience, Rakuten merchants will immediately see the benefits of being able to use a digital currency, including instant global reach with no cross-border fees, no price volatility, and no fraud, risk or chargebacks."
Rakuten has over the years been shopping abroad to reduce dependence on its home market.
Rakuten was among a clutch of investors that invested in San Francisco-based bitcoin-related startup Bitnet Technologies in October 2014.
In September 2014, the Japanese firm acquired US discount store Ebates.com for $1bn.
Other high-profile acquisitions include free messaging application Viber for $900m in February 2014 and Canadian e-book reader Kobo for $315m in 2011.