(Reuters) - Shares of ValueClick Inc plunged 29 percent after the online marketer posted quarterly revenue that missed estimates and forecast weak second-quarter revenue, saying some deals will not start contributing till later in the year.
The company's shares, which had rallied to a 4-year high of $21.60 on Tuesday, fell to $15.43 in Thursday morning trading, making them one of the biggest percentage losers on the Nasdaq.
The losses wiped off more than $500 million from ValueClick's market capitalization within the first hour of trading.
"Revenue shortfall was driven by greater-than-anticipated seasonality in the display business and ongoing weakness in the European affiliate marketing business," ThinkEquity analyst Robert Coolbrith said in a note.
The company's affiliate marketing unit allows advertisers to develop their own online sales force comprised of third-party publishers.
ValueClick, which competes with services from Yahoo Inc, Google and eBay Inc, forecast second-quarter revenue of $155 million to $160 million, compared with analysts' estimates of $167.
Analyst Coolbrith lowered his price target on the company's shares by $2 to $24, but maintained his "buy" rating.
Citigroup and BMO Capital Markets also cut their price targets on the stock.
(Reporting by Sayantani Ghosh in Bangalore; Editing by Anil D'Silva)