WALTHAM, Mass. (AP) ¿ Thermo Fisher Scientific Inc. said Thursday its profit shrank 35 percent in the first quarter due to writedowns of recently acquired assets and weaker sales of scientific instruments and lab equipment.

The company also reduced its forecast for the year because the world economy is "showing little sign of improvement."

In the three months ended March 28, Thermo Fisher earned $148.9 million, or 35 cents per share, down from $229.7 million, or 53 cents per share, in the year-ago period. Excluding one-time costs, its profit fell to 62 cents per share from 73 cents per share.

Revenue slid 12 percent, to $2.26 billion from $2.55 billion.

Analysts expected profit of 70 cents per share and $2.42 billion in revenue, according to a Thomson Reuters survey.

Thermo Fisher said amortization costs for acquistion-related assets totaled 24 cents per share in the first quarter. Thermo Fisher also recorded 3 cents per share in restructuring and other costs.

Revenue from the company's laboratory products and services segment fell 9 percent to $1.42 billion, and analytical technologies revenue fell 14 percent to $939 million.

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