Vivendi has reported a strong first half, with sales up 6.4% to €9.610 billion ($13.14 billion). But business was not quite as rosy at the French media conglomerate's Universal Music Group, where revenues were €2.095 billion ($2.86 billion), down 4.9% compared to the same period last year.

In a statement, Vivendi cited "adverse currency movements and difficult recorded music market conditions."

At constant currency, sales at UMG were broadly in line with last year and down just 0.3% due to markets in Europe -- particularly in the U.K. -- performing better than expected, Vivendi said.

Furthermore, UMG enjoyed higher music publishing revenues, including those from BMG Music Publishing, which it bought on May 25 this year. Excluding BMG Music Publishing, UMG revenues fell 2.5% at constant currency.

There was some good news in the digital market, however, with sales reaching €315 million ($430 million) in the first half, up 51% from last year at constant currency. Digital sales now represent 15% of total UMG revenues, up from 10.1% during the same period last year.

Bestsellers included albums from Nelly Furtado and Amy Winehouse, and new releases from Maroon 5, Mika and Fall Out Boy.

In the second quarter, UMG's posted revenues down slightly to €1.068 billion ($1.46 billion), with adverse currency movements broadly offset by incoming revenues from BMG Music Publishing.

The company says its relatively-stable second quarter reflected better-than-market performance particularly in Japan, higher music publishing revenues and strong growth once again in the digital sector.

Digital revenues in the second quarter rose 49% to €155 million ($212 million) at constant currency, with both online and mobile sectors reporting significant growth.