Expedia said Sunday that it offered 3.30 Australian dollars ($3.09) per share in cash, a 30 percent premium over Wotif's average price last week.
Wotif sells hotel bookings and air travel through brands including Wotif.com, lastminute.com.au and travel.com.au. The company had revenue of 76 million Australian dollars ($71.1 million) during the last six months of 2013.
Expedia said the deal needs the approval of Wotif shareholders and is expected to close in the fourth quarter.
Bellevue, Washington-based Expedia runs its own brand website and others such as Hotels.com and Hotwire. The company lost $14.3 million in the first quarter.