Sterling traded firm near an eight-week high against the dollar on Thursday, drawing support from steady economic growth in Britain, although a drop in business investment was likely to make some investors cautious, Reuters reported. Data released on Thursday showed firms' investments fell at their sharpest rate in nearly six years in the last quarter of 2014, hit by lower investment in the petroleum sector as global oil prices fell. British gross domestic product between October and December grew by a quarterly 0.5 percent, slowing from 0.7 percent in the third quarter. That was the slowest quarterly growth rate in a year, but was broadly in line with expectations, and much better than the euro zone. Sterling was a tad higher, trading at $1.5535, having hit a eight-week high of $1.5554 in Asia. The euro was also steady at 73.19 pence, not far from a 7-year low of 73.05 pence struck early in London trading.