Shares in Pharmaceutical Product Development (Nasdaq: PPDI) fell as much as $4 a share, or 18 percent, after the life science and drug development and contract services company cut its annual forecast for the coming year.

shares plunged under $17.50 a share after the firm said it expected a profit of between $1.54 and $1.60 a share for 2009. That was down from earlier forecasts of between $1.97 and $2.05. Analysts had forecast a $1.82 per share profit in a poll by Thomson Reuters.

By noon, shares recovered a bit to $18.28.

The rally continued into the afternoon Wednesday with PPDI closing at $18.50, a loss of $3.49 or 16 percent.

PPD said the world’s slowing economy led to the downward revisions.

Some of the loss of profit is due to PPD’s recent decision to sell its Piedmont development lab in Research Triangle Park.

PPD also cut its revenue forecast by $200 million to between $1.4 billion and $1.47 billion.

After the markets closed Tuesday, PPD disclosed first-quarter earnings of 38 cents per share on revenues of $364.9 million, down from $392.5 million a year earlier.