By Saabira Chaudhuri Thermo Fisher Scientific Inc.'s (TMO) second-quarter earnings fell 55% as the supplier of analytical technologies and laboratory products faced a tough comparison with a year-ago period that saw gains from business sales, though revenue climbed. The company cut its full-year revenue outlook to between $12.14 billion to $12.26 billion, citing discontinued operations, an acquisition and unfavorable foreign exchange. However, it raised its earnings estimate for the year to between $4.74 to $4.84 a share, citing new share buyback authorization among other reasons. In April, Thermo Fisher boosted its full-year earnings estimate to $4.71 to $4.83 a share on revenue of $12.27 billion to $12.43 billion. Thermo Fisher's sales have improved in recent quarters, aided by acquisitions and its expansion into Asia-Pacific markets. The company also launched new products last year to expand its mass spectrometry, specialty diagnostics and laboratory equipment lineup. But higher research and development costs, on top of restructuring and acquisition charges, have challenged its bottom line of late. Earlier this month, Thermo Fisher agreed to buy transplant diagnostics test provider One Lambda for $925 million in cash to boost its existing immunosuppressant monitoring assays business. In response to the news, three credit ratings firms lowered their investment-grade ratings on the company, citing the increased debt associated with the deal. At the same time, the company unveiled plans to repurchase an additional $500 million of stock through Dec. 31. Thermo Fisher reported a profit of $233.8 million, or 63 cents a share, down from $523.4 million, or $1.36 a share, a year earlier. The latest results included a $51.1 million loss on disposal of discontinued operations versus a previous-year $305.8 million gain. Excluding items such as asset amortization, restructuring and acquisition-related costs, earnings rose to $1.22 from 99 cents. Revenue jumped 8.9% to $3.11 billion. Analysts polled by Thomson Reuters had most recently forecast earnings of $1.16 on revenue of $3.05 billion. Operating margin rose to 11.8% from 9.3%. The laboratory products and services segment--the company's largest top-line contributor--saw a 2% revenue increase while its operating profit rose 0.6%. The analytical technologies segment's revenue jumped 8% and earnings grew 10%. Specialty diagnostics segment revenue increased 28%, while its income was up 47%. Shares closed at $49.78 Tuesday and were inactive premarket. The stock is down 23% over the past 12 months. Write to Saabira Chaudhuri at saabira.chaudhuri@dowjones.com Subscribe to WSJ: http://online.wsj.com?mod=djnwires