By Tom Bergin and Valentina Consiglio LONDON/ROME (Reuters) – Yahoo! Inc is shifting its main European tax base to Ireland from Switzerland, a Reuters examination of company statements and accounts shows, as pressure mounts on the Alpine nation to abolish some corporate tax incentives. Yahoo pays all taxes required and complies with tax laws in all countries where we operate. We take our tax obligations seriously, Yahoo spokeswoman Caroline Macleod-Smith said. However, tax experts said it was likely the changes that Switzerland is expected to make to its tax rules, following European Union pressure, had some influence over the decision, and that other companies could follow Yahoos lead.