STRASBOURG - Google and Amazon will have to tell companies how they rank products on their platforms while Facebook and other tech firms will have to be more transparent about their terms and conditions under new EU rules approved on Wednesday.

The platform-to-business (P2B) law, proposed by the European Commission in April last year, is the latest move by Europe to rein in online giants and ensure they treat smaller rivals and users fairly.

Lawmakers at the European Parliament gave the green light to the new laws on Wednesday, which will have to be rubber stamped by the European Council in the coming months before they take effect. Negotiators from all three bodies reached a political deal in February.

The new rules, which will cover 7,000 online companies, target e-commerce market places, app stores, social media and price comparison tools.

Google's three products Play, Shopping and Search, Apple's App Store, Microsoft's Store and Bing, Amazon Marketplace, eBay, Fnac Marketplace, Facebook's Instagram, Skyscanner, Yahoo! and DuckDuckGo are some of the companies affected by the rules.

"As the first-ever regulation in the world that addresses the challenges of business relations within the online platform economy, it is an important milestone of the Digital Single Market and lays the ground for future developments," Andrus Ansip, the Commission's digital chief, said.

The rules include a blacklist of unfair trading practices, require companies to set up an internal system to handle complaints and allow businesses to group together to sue platforms.

The tech industry, which successfully lobbied for the light regulatory regime, welcomed the lawmakers' endorsement.

"This new regulation will positively contribute to achieving the digital single market, while reinforcing trust and predictability online," tech lobbying group EDiMA said.

Its members include Amazon, Apple, eBay, Expedia, Facebook, Google, Microsoft and Mozilla.

(Reporting by Foo Yun Chee; Editing by Mark Potter) ((foo.yunchee@thomsonreuters.com; +32 2 287 6844; Reuters Messaging: foo.yunchee.thomsonreuters.com@reuters.net))