HOUSTON -- The French participation in a long-term Mars-exploration program remains in doubt following budget cuts at its space agency, CNES, and pending a government review of space-spending priorities.

What is clear is that CNES's Premier Mars mission, designed to include a Mars-orbiting satellite and four 18-kilogram landers to study the Martian surface and subsuface, will be substantially scaled back. The year-2007 launch date  likely will slip to 2009.

"We are looking for significant cost reductions to Premier, and a simplification of the mission," said Jean-Louis Counil, principal scientists for Mars exploration at CNES. "Our top priority remains the landers.

Second priority is to test techniques for a future Mars sample-return mission, and the third priority is orbital science."

CNES and NASA in the late 1990s had planned an ambitious Mars Sample Return mission that was first scheduled for launch in 2005, then 2007 and has recently been pushed back to at least 2011.

The French Research Ministry on Sept. 25 announced a 2.6 percent reduction to CNES's budget for 2003, continuing a trend of budget declines at the agency for the past five years. CNES and Research Ministry officials are now determining what to keep, what to scrap and what to postpone in a budget already expected to be dimished following expected new spending on launch vehicles.