London's top stocks are expected to open marginally higher, with traders forecasting a 3 point rise after the open.A big surge in business at Barclays Capital and decline in impairments had profit at Barclays bank up 47% in the first quarter of 2010. Profit before tax from continuing operations leapt to £1.82bn from £1.24bn in the first three months of 2009. Investment banking arm, Barclays Capital, raked in £1.47bn, 62% more than the year before.FT owner Pearson reports all parts of the company have made a good start to 2010 with first quarter revenues up 7% to £1.08bn or by 12% on a constant currency basis. "The first quarter is always a very light trading period for Pearson owing to the seasonal phasing of our book publishing businesses, and we expect these growth rates to moderate as we go through the year," it said.Advertising giant WPP said a stabilisation and subsequent growth in revenue came earlier than expected. Reported revenues were £2.078 billion in the first quarter, down just under 2% from last year. Revenues in constant currency were up 0.5%, reflecting the strength of the pound sterling against the US dollar and Euro. Trading at Davis Service Group has been in line with expectations in the first quarter with revenues broadly in line with the corresponding period of 2009. The laundry and workwear group said that, as expected, operating margins have improved as the effects of the cost cutting programme kick in.