Panmure Gordon has cut its rating for temporary power and temperature control services firm Aggreko from 'buy' to 'hold' following a recent site visit to the company's Americas operations.The broker said that the visit was positive overall with the economic outlook in the Americas more optimistic than previously thought.Panmure said the regional business is "setting the foundations for further growth with training programmes and efficiency drives which should enable it to drive deeper into existing sectors and also expand further into Latin America to take advantage of structural power shortages".However, the broker said: "until these potential prospects and opportunities translate to profits, we feel the shares look high enough after a recent run."It has left its forecasts for the company unchanged, estimating a 9.2% fall in earnings per share (EPS) this year to 83.5p, before a 4.6% increase in 2015 to 87.4p and 2.5% growth in 2016 to 89.6p.The stock's valuation - trading at 20.2 times 2014 estimated earnings - "looks up with events to us given the limited extent of EPS growth".The broker's target price of 1,748p suggests only marginal upside from current prices, it said.The shares were down 0.4% at 1,680p by 10:59.BC