surged Thursday after the Miami drug company guided 2005 earnings substantially higher.

The stock rose 9% even though the company's first-quarter earnings fell short of analysts' predictions and fell below results from the same period last year.

Ivax earned $33.5 million, or 12 cents a share, on revenue of $491.6 million for the three months ended March 31. For the first quarter of 2004, Ivax earned $42.3 million, or 16 cents a share, on revenue of $425.2 million.

The Wall Street consensus, according to Thomson First Call, had predicted a first-quarter 2005 profit of $39.8 million, or 14 cents a share, on revenue of $472 million. Ibax makes generic and brand-name drugs.

Ivax attributed the weaker earnings to a new accounting rule relating to the conversion of debt into 10 million shares of Ivax stock. The company said the earnings-per-share impact of the new rule "will be almost entirely eliminated in future quarters."

Investors appeared to focus more on the rising first-quarter sales than on the sliding first-quarter EPS. The stock climbed $1.66 to $19.21.

In less than 90 minutes of market activity, more than 2.2 million shares were traded -- just below the average daily trade of 2.3 million shares.

"As announced previously, we anticipated lower earnings in the first quarter 2005 that would be followed by higher earnings later in the year," said Neil Flanzraich, vice chairman and president. "In fact, first-quarter results exceeded our expectations."

The first-quarter results prompted the company to adjust its earnings predictions for 2005. Previously, it estimated an EPS in the range of 76 cents to 86 cents. Now, it says the EPS will be in the middle to upper range. The Thomson First Call consensus predicts 80 cents.

Ivax also reaffirmed guidance for 2006 in the range of $1.35 to $1.55. The Wall Street consensus is $1.36.