PARIS (Reuters) — Proposed strict capital rules for European Union-based insurers should be made flexible enough to suit the needs of companies in each EU country, European insurance lobby groups said on Friday.Their comments at a conference in Paris are a sign of growing industry resistance to a one-size-fits-all approach to the so-called Solvency II rules, designed to make insurers financially stronger by making them hold capital in strict proportion to the risks they cover.Speaking to journalists, top insurance representatives from France, Italy, Belgium and several other EU countries called for a nation-by-nation approach."The proposals must correspond to every market," said Jean-Francois Lequoy, head of the French Insurers Federation.Solvency II has been held up by disagreements between EU countries over how capital requirements for life insurers should be calculated, with each government championing the method that favours its own insurance industry.Some executives have said efforts to agree a harmonised set of rules should be scrapped in favour of a looser arrangement that gives insurers in each country some leeway to calculate their capital levels in a way that suits them.One solution could be exemptions for certain products in certain markets, while still keeping an overall Europe-wide framework, Belgian insurance industry representative Rene Dhondt said.European life insurers sell life and savings policies with varying durations and offering customers different rates of return, depending on local regulations and consumer preferences, leading to divergent capital requirements.Poland, for example, lacks the very long-term contracts offered in other countries, said Polish industry representative Grzegorz Pradzynski.British and Dutch insurers also stand apart because they are major providers of annuities, investment policies that offer a regular income for the duration of the customer's lifetime that are less common in other European countries.French Finance Minister Pierre Moscovici said he shared insurers' concerns the new rules might impose prohibitively high capital charges on some investment assets, hindering their ability to finance the private sector."I will take care to defend (insurers') interests because they are our interests as well, namely the financing of the French economy," he said.The European Commission, the architect of the Solvency II project, in September asked regulators to make sure the rules did not deter insurers from putting money into "growth and job-enhancing areas".Solvency II, originally intended to come into force in October 2012, is now not expected to take effect until 2016 at the earliest as wrangling over the rules final shape continues.Insurers, while broadly supportive of Solvency II, have complained that the delay prolongs uncertainty over their future capital requirements, potentially deterring investment in the sector.