MILAN (Reuters) - Lone Star, Christofferson Robb & Co (CRC) and other specialised investors have presented non-binding offers to buy a platform that will manage part of Monte dei Paschi di Siena's (>> Banca Monte dei Paschi di Siena SpA) bad loans, three sources close to the matter said.

The Tuscan bank is selling its 27.7 billion euro (£23.84 billion) portfolio of loans to insolvent borrowers in a complex securitisation scheme, part of a broader rescue plan aimed at addressing regulatory concerns over its financial stability.

Monte dei Paschi is working with Italian investment bank Mediobanca (>> Mediobanca Group) to set up a platform to manage its portfolio and bring in a partner to improve collections.

The sources said on Friday that offers had come from a consortium comprising U.S.-based Lone Star and Italian servicer Caf, and a second group made up of CRC and Italian real estate group Prelios (>> Prelios SpA).

Other bids were presented by Cerved Credit Management (>> Cerved Information Solutions SpA), KKR (>> KKR & Co. L.P.) and Vaerde Partners, sources said, without disclosing whether two or more of these bidders were working together.

The portfolio of bad loans to be managed by the platform will likely be worth around 9 billion euros, one of the sources said.

All involved parties declined to comment or were not immediately available for a comment.

(Reporting by Massimo Gaia and Elisa Anzolin; writing by Francesca Landini; Editing by Crispian Balmer)