Online travel research company TripAdvisor Inc reported a lower-than-expected quarterly profit, sending its shares down sharply in extended trading Wednesday.

Total selling and marketing costs rose 53 percent to $127 million in the second quarter ended June 30.

Net income rose to $68 million, or 47 cents per share, from $67 million, or 46 cents per share, a year earlier.

Excluding items, TripAdvisor earned 55 cents per share, 6 cents below what analysts on average had expected, according to Thomson Reuters I/B/E/S.

Revenue rose about 31 percent to $323 million, helped by higher income from referrals to booking sites.

TripAdvisor's shares were down 11.5 percent at $95 in after-hours trading, after ending the regular Nasdaq session up 3.1 percent at $107.36.