The European Union¡¯s record $5 billion fine against Google, levied Wednesday morning, marks the biggest regulatory attack yet on technology giants. But investors and analysts largely shrugged off the ruling¡¯s potential to immediately dent Google¡¯s business.

The real damage will hinge on how aggressively the EU cracks down on Google¡¯s lucrative agreements with smartphone-makers and carriers going forward ¡ª and how quickly Google rivals like Amazon and Microsoft pounce. Amazon and Samsung Electronics, a Google partner, have already started pushing into web search with their voice-activated products.

As expected, the European Commission declared Google¡¯s conduct with its Android mobile operating system anti-competitive and ordered the company to cease its behavior, suggesting it change its contracts with phone-makers. That targets Android¡¯s greatest asset for Google: the way it distributes its lucrative services, such as search, its web browser and its app store, to more than a billion devices. The European ruling took direct aim at those three services.