* Unions expect thousands to join Paris protest march
* Voices call for outright nationalisation to save jobs
PARIS, Sept 13 (Reuters) - Irate staff at Credit Immobilier de France (CIF) will take to the streets of Paris on Thursday to call for a full nationalisation of the troubled French mortgage lender and a guarantee to protect its 2,500 jobs.
CIF, which has 33 billion euros ($42.5 billion) in assets and a mortgage market share of 3.5 percent, had for months been seen as a liability to the French banking system after credit-rating agency Moody's warned its dependence on crisis-racked funding markets exposed it to a major financing crunch.
It was thrown a state lifeline on Sept. 1 after a fruitless search for a buyer.
Thursday's march, which unions hope will attract the majority of CIF's employees, comes at a time of record unemployment in France and sinking poll ratings for President Francois Hollande.
Although staff representatives say Hollande's promise to guarantee CIF's debts saved it from a messy bankruptcy, they view the bailout as only going half way. Only nationalisation, they say, will remove the risk of job cuts to placate EU regulators and protect French finances at a time of crisis.
"There is an alternative solution (to winding down the bank) that would allow CIF to keep operating," SNB union head Regis dos Santos said. "CIF must be made the core component of a new state-owned housing bank."
Funding for a nationalised CIF could be supplied by state bank Caisse des Depots, according to dos Santos, and would ensure the flow of credit to low-income borrowers buying flats in social housing favoured by CIF, he added.
Separately, Claude Sadoun, the former boss of CIF, whom many blame for driving the bank into the wall, also called on Thursday for the French state to turn the bank into a "public player" dedicated to housing.
"There must be a future for CIF," he told daily Le Figaro. "It is not too late to study tying CIF to a state-owned institution."
Sadoun received a compensation package after the state rescue forced him out. The payoff amounts to 15 months' salary, CIF said, which at 2011 levels would be around 675,000 euros. ($1=0.7759 euros) (Reporting by Lionel Laurent and Dominique Vidalon; Editing by Mike Nesbit)