Having already slashed key interest rates to below zero and pumped massive amounts of cash into financial markets, it started to directly finance businesses by buying their debt in the bond market.
In the first major trades, the ECB bought millions of euros worth of bonds of French power company Engie and Spain's Telefonica, reported the Bloomberg financial news wire, citing unnamed market players.
Other purchases were of debt issued by Belgian-Brazilian brewer Anheuser-Busch InBev, German engineering giant Siemens, Italian insurer Assicurazioni Generali and French automaker Renault, Bloomberg said.
The Frankfurt-based bank wants companies to use the extra cash to boost investment, creating jobs and growth in the flagging 19-country currency bloc.
With prices currently falling, the ECB hopes to raise inflation back to close to two percent, a level it deems healthy for growth.
In a sign the ECB's shopping spree was having an impact, traders said bond yields -- which are inverse to their prices -- fell to fresh lows in the eurozone corporate bond market today, while the yield of the benchmark 10-year German Bund was was hovering at a record low at just above zero.
Some also fear that large companies -- which already have access to cheap money thanks to rock-bottom interest rates -- could be tempted to use the extra liquidity for risky merger and take-over gambles.
