MADRID, Feb 12 (Reuters) - Talgo shares fell as they resumed trade on Monday morning after its potential bidder, Hungary's Ganz Mavag (Magyar Vagon), said on Friday there were no assurances it would make an offer for the train maker.

The shares, which were suspended by the Spanish stock market regulator on Thursday, were down 4.8% to 4.55 euros ($4.90) at 0926 GMT, after opening down 8%.

The website El Confidencial had reported that Magyar Vagon was planning to make an offer for Talgo at 5 euros per share, pushing the stock up almost 10% that day and eventually prompting a suspension of trading by the regulator.

On Friday evening, the Hungarian firm confirmed its interest in a 5 euro per share offer, but said it had not made a final decision as it was discussing how to finance a possible deal.

"There are no assurances that a takeover bid for Talgo's shares will be launched," it said in the filing.

A 5 euros per share bid would value Talgo, Spain's second largest train manufacturer after CAF, at 632 million euros.

Talgo makes the long-nosed bullet trains operated by Spanish state-owned operator Renfe as well as suburban and regional trains.

($1 = 0.9283 euros) (Reporting by Inti Landauro Editing by Jason Neely and Mark Potter)