By Giuseppe Fonte and Elisa Anzolin
ROME/MILAN, Feb 28 (Reuters) - Italy must block any attempt by the London Stock Exchange to break up the Milan Bourse as it seeks antitrust approval for its $27 billion acquisition of analytics company Refinitiv, a lawmaker from the ruling 5-Star Movement told Reuters on Friday.
Davide Zanichelli of the lower house finance committee, said he had asked the government to clarify in parliament what it planned to do in order to protect the Milan bourse, which controls the domestic government bond trading platform MTS.
Speculation about the LSE's plans for its Italian unit Borsa Italiana has grown since it announced last year that it planned to buy Refinitiv, in which Thomson Reuters, the parent of Reuters News, holds a 45% stake.
A sale of assets to European rivals in coming months is among potential options to gain antitrust approval and to fund the deal.
The ruling 5-Star and centre-left Democratic Party (PD) coalition considers Borsa Italiana a strategic asset because of the importance of the MTS platform in handling the trading of Italian government debt.
Pan-European stock market operator Euronext has already expressed an interest in buying the exchange should it be put up for sale.
"Five-Star has no prejudicial objection against Euronext but the party does not want the country's stock exchange to become a minor province of Paris," Zanichelli said.
David Schwimmer, the former Goldman Sachs veteran who took over the reins at the LSE in 2018, said on Friday he was not expecting a change in the ownership of Borsa Italiana.
Zanichelli suggested state lender Cassa Depositi e Prestiti (CDP) and other investors could buy back the group from LSE to return control to Italy.
Bank of Italy governor Ignazio Visco signalled early this month that national authorities were closely monitoring each step in the takeover negotiations.
Late in December Economy Minister Roberto Gualtieri and Treasury General Director Alessandro Rivera, held talks with Schwimmer, sources said.
An official familiar with the matter told Reuters the Italian Treasury was reviewing possible scenarios regarding the ownership structure of the Milan bourse and MTS particularly.
With public debt at 135% of gross domestic product, proportionally the highest in the euro zone after Greece, Italy is keen to maintain control over the decision-making processes on everything related to government bond trading, the source said. (Editing by James Mackenzie; Editing by Kirsten Donovan)