The U.K. Parliament released on Wednesday a trove of internal Facebook Inc. emails that show Mark Zuckerberg and other executives pursuing hard-nosed tactics to stifle competitors, as well as considering a range of possibilities for monetizing the massive amounts of data the company collected on its users.

The documents show that Facebook gave some third-party developers special access to user data and several years ago contemplated charging developers for data access, a step that would have marked a dramatic shift away from the social-media giant’s policy of not selling that information. The emails also reveal that Mr. Zuckerberg, an engineer and software developer by background, was deeply involved in business decisions at Facebook as it grew into a global platform with more than 2 billion users.

Many of the emails are excerpted and their full context isn’t clear. But the documents could present fresh problems for the company as it faces a range of regulatory inquiries on both sides of the Atlantic into how it safeguards user privacy, treats its competitors and controls access to its platform.

In a Facebook post Wednesday, Mr. Zuckerberg said: “Like any organization, we had a lot of internal discussion and people raised different ideas. Ultimately, we decided on a model where we continued to provide the developer platform for free and developers could choose to buy ads if they wanted. This model has worked well.”

The Facebook chief executive said many of the changes discussed were rooted in the company’s efforts in 2014 and 2015 to rid the platform of abusive and “sketchy” apps, while also building a business model that was profitable and sustainable.