A joint European-Russian plan for an unmanned mission to look for signs of life on Mars cleared a hurdle at a European Space Agency (ESA) budget meeting in Naples on Wednesday, delegates said.

But a scheme to send a European lander to the Moon made no headway given ESA's money crunch, and an early-stage proposal to join China in a space weather forecasting system was also nixed, they said.

The meeting in the southern Italian city is to set a multi-year budget for ESA at a time when financial constraints are forcing European governments to scrutinise space projects closely before giving them the green light.

ESA's ExoMars mission was born in December 2005 and more than 400 million euros ($500 million) has been spent on it so far.

It calls for sending an orbital probe to Mars in 2016 that would look for traces of methane gas and other biological clues in the Red Planet's atmosphere, followed by a six-wheeled rover in 2018.

The scheme was badly hit in February this year when NASA pulled out, prompting Europe to turn to Russia for help.

Under a draft deal, Russia will provide heavy-lift Proton rockets for the launches and in return get instrument space onboard the satellite and rover.

The scheme was given the nod at ESA's ministerial-level meeting that began on Tuesday, provided both sides sign a formal contract by the end of the year.

"There are a few things that have got to be nailed down," a source told AFP on the final day of the meeting.

"It's a pity that we've lost the partnership with NASA but it's good that we've now got the Russians coming in instead, so we're optimistic that this is now on track," British Science Minister David Willetts said.

Separately, a 500-million-euro ($600-million) project proposed by Astrium, part of the giant EADS aerospace corporation, to send an automated lander to the Moon's south pole in 2019 is unlikely to be taken up in ESA's upcoming three-year budget, delegates said.

The lander would test technologies for "soft and precise" landings that would help future human missions to the Moon.

"It's not gained sufficient support. It's out of the proposals for the time being," ESA spokesman Franco Bonacina told AFP.

Another proposal, to team up with China in a three-satellite space weather forecasting system called KuaFu, "is pretty much off the table," a delegate told AFP.

"This was predictable, it's not the direction we want to go for observation satellites," he said, pointing out that the idea was only at the blueprint stage.