Covance ( CVD), a drug development services company, said its earnings rose 18.5% for the second quarter, driven by new business orders and strong performance in its central laboratory and commercialization services. The company earned $35.02 million, or 54 cents a share, compared with $29.55 million, or 46 cents a share, a year earlier. Earnings included stock option expense of 4 cents a share. Analysts polled by Thomson First Call were expecting earnings of 53 cents a share. Second-quarter net revenue rose 14% from a year ago to $335.24 million as against analysts' expectation of $335.77 million. For the full year, the company raised earnings guidance to at least $2.19 a share from $2.16 a share. Analysts also forecast earnings of $2.19 a share. The company's early development segment revenue was $155.7 million, up 11.4%. Revenue of the late-stage development segment, which includes central laboratory and commercialization services, rose 16.4% to $179.5 million. The company's backlog at end of the quarter was $1.97 billion, up 31.2% from last year. Net orders in the second quarter were $555 million, up 55.8%.