French companies have so far absorbed the shock from the conflict in the Middle East, but pervasive uncertainty and higher energy costs are beginning to test the economy's resilience, the central bank said on Tuesday in its monthly business survey. The Bank of France said there was so much uncertainty over the outlook that it could not provide its usual growth estimate for the quarter. It said, however, that activity continued to expand in April, albeit more slowly, according to its April 28 to May 6 survey of around 8,500 firms.