June 20 - Jefferies Group Inc. (Jefferies) reported weaker second quarter 2012 results due to a more challenging market environment, further reduction in M&A activity and certain one-time items. Generally, fixed income has maintained some of the momentum gained during 1Q12 and exceeded Fitch's expectations. However, the equities business remains challenged amid poor market conditions, which are likely to persist. Fitch's ratings already take into account some of the volatility inherent in