* French president delivers speech on future of Europe
* Macron lays out ideas for overhauling euro zone, security
* Speech touches on defence, immigration, tax, social policy
* Franco-German ambitions may be limited by German election (Adds quotes, reaction from European Commission)
PARIS, Sept 26 (Reuters) - President Emmanuel Macron offered an ambitious vision for European renewal on Tuesday, calling for the EU to work more closely on defence and immigration and for the euro zone to have its own budget, ideas he may struggle to implement.
In a nearly two-hour speech delivered two days after the German election in which Chancellor Angela Merkel's alliance underperformed, limiting her freedom to manoeuvre on Europe, the 39-year-old French president held little back in terms of sweep, self-assurance and aspiration.
But at a time when Europe is beset by tensions between east and west and battling to overcome nearly a decade of economic crisis, Macron's earnest and at times high-brow discourse ran the risk of falling on deaf ears.
Speaking at the Sorbonne, he portrayed Europe as needing to relaunch itself, saying that on issues as diverse as asylum, border protection, corporate tax, intelligence sharing, defence and financial stability it needed much deeper cooperation.
"The only path that assures our future is the rebuilding of a Europe that is sovereign, united and democratic," the former investment banker and philosophy student said, flanked by a French and a European Union flag.
"At the beginning of the next decade, Europe must have a joint intervention force, a common defence budget and a joint doctrine for action."
In his campaign for the presidency, Macron made European reform a central plank and he and Merkel have spoken about their desire for France and Germany, the European Union's two largest economies and often the engines of change, to take the lead on integration.
But five months into his five-year term, Macron faces the threat that Merkel, 63 and looking to start her fourth term, has less capacity to move than either would have hoped.
Her CDU/CSU alliance is still the largest bloc in the Bundestag, but to build a working majority she will likely have to form a coalition with the liberal Free Democrats (FDP), who are opposed to many of Macron's ideas, and the Greens.
Rather than tailoring his speech to fit the contours of what the FDP, the Greens or Merkel may have wanted to have heard, Macron kept his vision broad and far-reaching, while also detailing some specific ideas for an improved euro zone.
"A budget can only go hand-in-hand with strong political leadership led by a common (finance) minister and a strong parliamentary supervision at the European level," he said, emphasising the need for democratic accountability.
"A durable economic power can only be built around a single currency. It is from this economic and monetary union that we can create an integrated Europe."
The fiscally conservative FDP dislikes the idea of a euro zone budget or any facility that may lead to financial transfers from wealthier euro zone countries to poorer ones, as well as the possibility of national debt being pooled.
The FDP has also called for phasing out Europe's ESM bailout fund, which Macron wants to turn into a European Monetary Fund, and wants to see changes to EU treaties that would allow countries to leave the euro zone.
Not shying away from addressing Germany directly even as it tries to deal with the fallout from Sunday's election, Macron set an objective that the two countries completely integrate their markets and corporate rules by 2024.
"We share the same European ambitions and I know her commitment to Europe," he said of Merkel. "I'm proposing to Germany a new partnership. We will not agree on everything, not immediately, but we will discuss everything."
In Berlin on Monday, in a reference to Macron's speech, Merkel said it was important to move beyond catchphrases and provide detail on how Europe could be improved. It was not immediately clear whether Macron had managed to go beyond slogans as far as Merkel was concerned.
But Martin Selmayr, the chief of staff of European Commission President Jean-Claude Juncker, said the proposals to reinforce the euro zone would be discussed alongside Juncker's own at a special euro zone summit planned for December.
"A very European speech, very open," Selmayr tweeted in French.
Ahead of his speech, Elysee officials said Macron hoped his ideas would be taken into account in Germany's coalition building negotiations. Those talks are not expected to begin until mid-October and may take several months.
Macron's thinking appears to be to get his boldest ideas out and into the discussion before the coalition agreement takes shape. German coalition deals are strict, setting red lines for how far the chancellor can manoeuvre and therefore limiting the scope of any Franco-German initiatives. (Additional reporting by Sudip Kar-Gupta and Bate Felix; Writing by Luke Baker; Editing by Janet Lawrence)