Rising costs for commodities and raw materials have driven some U.S. companies to hike prices, the U.S. Federal Reserve reported in its latest Beige Book released Wednesday. Wage pressures, however, remain subdued as March unemployment lingers at 8.8 percent, the central bank said.

The report shows modest but widespread economic improvement led by strong manufacturing sector growth. It also notes mounting uncertainty and anxiety among U.S. businesses about rising oil prices and disruptions to sales and production due to conflict in the Middle East and the natural disasters and nuclear crisis in Japan.

Fed banks in Boston, Philadelphia, Richmond, Atlanta, Chicago, Minneapolis, and Dallas all said companies in their region had saw or predict sales and production disruptions as a result of the tragedy in Japan.

The Beige Book, published by the Fed eight times a year, provides a survey of economic conditions in each of the 12 Federal Reserve Banking Districts and is used to set monetary policy at monthly meetings of the Federal Open Market Committee.

The FOMC will consult this week's report when it meets to set U.S. macroeconomic policy April 26 and 27.

美联储周三发布的褐皮书经济报告称不断增涨的大宗货物成本和原材料价格导致部分美国产品价格上涨。美国失业率三月徘徊在8.8%，薪资压力成为阻碍其下降的绊脚石。

褐皮书中指出美国经济持续改善得益于制造业的带头增长。同时报告还指出，很多公司担心北非和中东的骚乱可能导致油价进一步上涨。他们也对日本地震和核危机的影响感到不安。

波士顿、费城、里士满、亚特兰大、芝加哥、明尼阿波利斯和达拉斯联储都报称其所在地区的销售和生产活动因受日本地震的影响而中断或预计中断。

褐皮书每年发布八次，是美国联邦储备委员会的美国经济展望调查报告，该报告包含12地区联储分行所提出的地区经济情况摘要。该报告为联邦公开市场委员会每月例会提供政策制定依据。

联邦公开市场委员将与4月26，27两天就本周报告对美国宏观经济政策进行调整。