Rail distribution platform SilverRail Technologies is now majority owned by Expedia Inc.
Terms have not been disclosed.
The deal marks the end of an eight-year journey as an independent business for the UK-based company.
SilverRail was created by Aaron Gowell (CEO) and Will Phillipson (president) in 2009, billed initially as a GDS for trains, which has since expanded to offices in Sweden, Australia and the US.
SilverRail previously had a consumer-facing play in the shape of Quno, but this was discontinued within a few years.
The company has raised a hefty $69 million over the course of four rounds since its inception (TLabs here), in a bid to push its rail ticketing and train operator distribution platform.
The most recent investment came in April 2014 when Mithril Capital Management led a massive round of $40 million that also featured previous backers Canaan Partners, Sutter Hill Ventures, and Brook Venture Partners.
Gowell had earlier managed to attract $29 million in seed and series A and B funding, as well as a $3 million as part of a tuck-in acquisition.
The $40 million Series C was considered a monster round when compared with the industrywide median for Series C, according to a report at the time by research firm Pitchbook.
SilverRail's most high-profile partnership to date was probably with Expedia, when it secured an agreement to power search and ticketing of rail services on the online travel agency.
Orbitz-owned Ebookers (both now part of the Expedia empire) was the first major OTA to work with SilverRail.
Phillipson had previously worked for Wandrian, a US-based startup with much the same mission as SilverRail.
Expedia Inc CEO, Dara Khosrowshahi, says:
"Rail is ready for an online revolution, and we're ready to be a part of it. Rail's shift online is one of the fastest growing areas of innovation in the $1.3 trillion travel market, and SilverRail is powering that innovation.
"We are tremendously excited to welcome the incredibly talented SilverRail team into the Expedia family."