Utility group National Grid has maintained its outlook for the full-year following a 'solid' period of trading since the start of April. The group said the UK had made progress in delivering operational efficiencies and progressing with its investment programme, while in the US it saw a good operational performance, where it had also filed for increased KEDLI capital investment allowances. Capital expenditure for the year at constant currency is expected to be similiar to the £3.4bn invested the prior year, when it helped drive a 5% increase in growth in regulated assets. Some spending may be held back in the UK due to delays in the cable manufacturing process for a circuit connecting North Wales to Scotland, although the impact of this is not expected to be significant. In the US, investment is set to be marginally higher than last year."Our businesses have continued to build on the performance improvements of 2013/14 and, as a result, have started the year well," Chief Executive Steve Holliday said. "In the UK, we have progressed our investment programme, enhancing the overall condition of our assets and improving their environmental and safety characteristics. We continue to develop innovative ways to deliver the essential outputs required more efficiently, maximise our performance under the RIIO model and generate savings for consumers. "In the US, we are sustaining our focus on improving customer service and managing costs in preparation for further rate filings in 2015. I am pleased that we were able to install the major upgrade of our US systems on time, a major milestone in our extended implementation process and early signs that this has gone well are encouraging."After the progress seen in the four-month period, the group is maintaining its outlook for 2014/15, saying it expects to deliver another year of solid operating and financial performance as well as asset growth, which it added would be "consistent with sustaining our long-term dividend policy". Shares inched 0.06% lower to 870.50p early on.NR