Sovereign funds wanting to buy shares in Italian companies should "generally" stay below 5 percent, Italian Foreign Minister Franco Frattini has said.

Frattini's comments, in an Il Messaggero newspaper an interview, come after Italy's former colony Libya bought a 4.23 percent stake in No 2 Italian bank UniCredit last week -- a move which several Italian media reports said must have had the blessing of the Rome government.

Libya's central bank governor told an Italian newspaper at the weekend it planned to increase that stake to 5 percent.

"Italy trusts funds that operate in a transparent way, that aim to invest and not to control companies and therefore generally remain below five percent," Frattini told Il Messaggero.

Frattini said during a visit to the UAE at the weekend that the Italian government would negotiate directly with sovereign funds seeking to invest in Italy to prevent them from making unwelcome purchases.

"In the Emirates, they are the first ones who do not want to follow a path that is not linear. It's the first time they are dealing with a government rather than a merchant bank, and this is a guarantee for them too," Frattini said.

"The Libyan investment in UniCredit goes in the same direction, even though in that case it is not properly a sovereign fund," he said, without elaborating.

Last week's stake purchase in UniCredit was carried out by the Central Bank of Libya, the Libyan Investment Authority and the Libyan Foreign Bank.

Together they bought 3.67 percent of the Italian bank, adding to a 0.56 percent stake held since 1997 by the Libyan Foreign Bank and becoming UniCredit's second biggest shareholder. -Reuters