ValueClick Inc., an online advertising company that raised $76 million when it first sold shares to the public in March 2000, agreed to buy Mediaplex Inc. for $47.4 million in stock.
Westlake Village-based ValueClick said it will exchange 0.4113 share for each Mediaplex share, issuing 14.9 million shares for the deal. The offer values Mediaplex shares at $1.32, 45% more than its closing price Friday. Mediaplex shares rose 15 cents, or 16%, to $1.06 on Nasdaq.
San Francisco-based Mediaplex provides Internet banner advertisements and e-mail marketing.
New York-based DoubleClick Inc. has a 22% stake in ValueClick.
ValueClick shares, which have dropped 71% in the last year, fell 35 cents to $2.85 on Nasdaq.