A potential loan by the Czech central bank to the IMF as part of a European package to help the euro zone out of its debt crisis would lock up too much of the country's foreign exchange reserves, Czech central bank Governor Miroslav Singer said.

The Czech share of the original planned sum of the 200 billion euros (168 billion pounds) cash boost for the International Monetary Fund, proposed at an EU summit on Dec 9, was about 3.5 billion euros.

But European finance ministers agreed on Monday countries outside the euro zone, including the Czech Republic, which had been expected to prop up the fund's resources by a total of 50 billion euros, would not pay anything for now as their contributions first had to be approved domestically.

The euro zone ministers agreed to boost the resources by 150 billion euros and it was unclear if the bloc would reach its original target.

In an opinion piece written before the Monday deal and released at daily Hospodarske Noviny on Tuesday, Singer said the original 3.5 billion euros would hike total Czech IMF exposure to nearly a quarter of foreign exchange reserves, which was not safe at the present tumultuous times in global economy.

He said trade flows in Europe were changing dramatically.

Therefore the likelihood is growing that our economy, strongly dependent on foreign trade, can benefit significantly from its foreign exchange reserves, he wrote.

Singer also said that while euro zone countries faced no risk in providing a loan to the fund because they could tap euro liquidity from the European Central Bank, non-euro members of the European Union were in a different situation.

Countries outside the euro zone, like the Czech Republic, have no such access to euro liquidity and by using their foreign exchange reserves, they face an additional risk, Singer wrote.

Risks faced by countries of the euro zone in providing the loan are much lower than risks of countries outside it, even though the rationale behind determining the (level of) contributions is the same for everybody, he said.

Considering such a scheme fair is clearly against common sense, he added.

Czech Prime Minister Petr Necas has said the government needed more time and in-depth analyses to decide whether the Czechs would lend the fund anything.

Finance Minister Miroslav Kalousek said on Monday reports stating that the Czech Republic provide funds to the IMF were inaccurate because the government had not yet decided.

(Reporting by Jana Mlcochova; editing by Anna Willard)