What: Shares of Ctrip.com International (NASDAQ:CTRP) and fellow Chinese mobile and online travel specialist Qunar Cayman Islands (NASDAQ:QUNR) were up 21% and 16%, respectively, as of 12:30 p.m. Monday after Ctrip announced the completion of a share exchange with Baidu (NASDAQ:BIDU). Shares of Baidu were also up around 6% on the news.

So what: Specifically, Ctrip announced Baidu has exchanged 178,702,519 Class A shares and 11,450,000 Class B shares of Qunar Cayman Islands owned by Baidu for 11,488,381 newly issued shares of Ctrip. That equates to a share-exchange ratio of roughly 0.725 Ctrip American depositary shares (ADS) per Qunar ADS.

Consequently, Baidu will own shares representing roughly 25% of Ctrip's aggregate voting interest, while Ctrip will own shares representing around 45% of Qunar's voting interest.

"As the technology leading player in the industry," added Qunar CEO CC Zhuang, "Qunar has become China's fourth-largest e-commerce company with tremendous growth momentum. We are very proud of our team, and appreciate the support from our global shareholder base."

"This milestone transaction will enable us to focus on providing the best travel products and services to our travelers," stated Ctrip CEO James Liang. "We believe this will create greater value to our customers, partners and shareholders in the future."

Now what: Baidu and Ctrip have also agreed to a "business cooperation across a broad base of products and services," and Baidu voiced its intention to continue cooperating with Qunar. Recall Baidu was already Qunar's single largest shareholder, and just last month the two companies moved to deepen their existing strategic alliance, including the expansion of Quna'rs board of directors to include three Baidu executives.

Arguably more interesting, however, is that the deal came less than six months after Qunar received -- and subsequently declined -- an unsolicited offer from Ctrip.com, opting instead to take a $500 million investment from Silver Lake and another unnamed investor to help "expand its mobile presence, grow business lines, and further enhance technology capabilities." But Qunar also told investors it remained "open to engaging in further discussions with Ctrip as well as with other strategic players in our sector."

Meanwhile, Ctrip stock also flew higher in May after it revealed it had acquired a strategic stake in another smaller China-based competitor, eLong (NASDAQ: LONG).

Of course, the exact details regarding collaboration under this latest tie-up remain unclear. But it does ease investors' concerns over intensifying competition and rising marketing costs required for any given business to grow and maintain market share in the burgeoning Chinese travel industry. As a result, I can't blame the market for so aggressively bidding up shares of all three companies today.

Steve Symington has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Baidu. The Motley Fool recommends Ctrip.com International. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.