Corporate investment decisions are among the most important decisions of a firm. Internal capital markets play a key role in facilitating the allocation of capital resources in order to finance investment projects within diversified firms. This thesis investigates internal capital markets and its relationship with analysts earnings forecast errors in three countries with two distinct financial systems, namely, the market-based and bank-based financial system. Using segment level data for public listed companies in the UK, France and Germany between 2005 and 2010, we examine the operation and efficiency of internal capital markets in market- and bank-based systems. We also examine the impact of the financial crisis of 2008 on internal capital markets and analysts earnings forecasts errors, namely, the accuracy, bias and dispersion. The findings indicate internal capital markets actively facilitate the allocation of resources within diversified firms and, in general, operate inefficiently. Furthermore, internal capital markets appear to be more active in France compared with the UK. On the other hand, their role appears to be limited in Germany, as segments appear to rely more on their own resources and less on internal capital markets for investments. In addition, we find that internal capital market activity declines and efficiency improves during the financial crisis in UK. In contrast, there is no significant evidence to suggest that efficiency improves during the crisis in France or Germany. This research also finds some evidence to suggest internal capital markets operations aggravate firm complexity and, in turn, negatively affect short-term forecast accuracy in the UK. In addition to this, our analysis shows there is a positive relationship between the size of internal capital markets and dispersion in analysts earnings forecasts. In general, our study shows analysts are optimistic about firms future performance; however, the level of optimism significantly declines during the financial crisis. Lastly, we report a positive relationship between efficiency of internal capital markets and optimism in earnings forecasts.