Moscovici, addressing a press conference in central London after holding regular talks with British counterpart George Osborne, added that the BAE/EADS tie-up raised "a lot of questions" which needed to be resolved.
"We are examining the project" alongside the German government, the finance minister told reporters.
"We are asking a lot of questions concerning strategic interests of such a merger, the industrial effect, the possible synergies, the governance of the entity, the future of our defence industry, and employment," he said.
Moscovici added that "it will take time" to address these various issues which must be "examined thoroughly and discreetly".
BAE Systems and EADS announced last Wednesday that they were in merger talks to create a global aerospace and defence leader that would compete more effectively against rival US giant Boeing.
The two groups face a deadline of October 10 to finalise their projected $45-billion blockbuster merger deal that would create the world's biggest aerospace company.
The French and German governments hold big stakes in EADS, while the British state has a golden share in BAE that allows it to veto deals that it perceives not to be in the public interest.
Under the plan being discussed, the two groups would issue special golden shares in BAE Systems and EADS to each of the French, German and British governments.
The talks then envisage BAE Systems owning 40 percent of the enlarged group, with EADS holding a 60-percent stake.