Google announced a change in its executive ranks Wednesday that could have broad implications for the mobile business.

Andy Rubin, who had been senior vice president in charge of Android, Google’s mobile operating system, has been replaced by Sundar Pichai. Pichai is the senior vice president of Chrome and will now oversee Android as well.

Google has been in a confusing position because it has two unrelated operating systems: Chrome and Android.

At first, Google said they were separate: Chrome was for computers and the Web, and Android was for touch-screen mobile devices and apps.

But the lines among devices have blurred. Now, some computers (like the Chromebook Pixel that Google introduced last month) have touch screens, and people use mobile devices the way they used to use computers.

The personnel change is a sign that Google sees the need to somehow coordinate or merge the two operating systems.

Although Android has been wildly successful, with 750 million devices activated worldwide, computers running Chrome’s operating system have not.

At a media event to introduce the new Chromebook, Pichai drew less of a distinction between the two operating systems than Google executives had in the past.

‘‘So far, we have been in a world which has been pretty straightforward: Android phones and tablets and Chrome laptops,’’ Pichai said. ‘‘But lines do blur.’’

‘‘The way we think about it internally,’’ he said, ‘‘is as a user, you sign in to both these devices, you use search, Maps, Gmail’’ and other Google products. ‘‘All your Google services work seamlessly across devices.’’

The company did not provide any details about how Chrome or Android might change under the new leadership.

‘‘Today we’re living in a new computing environment,’’ Larry Page, Google’s chief executive, wrote in a company blog post announcing the change. ‘‘People are really excited about technology and spending a lot of money on devices.’’

Pichai has had a fast rise at Google and has experience developing hardware, a new area of focus for the company. In addition to Chrome and Android, he also oversees Google apps, like Gmail and Drive, for consumers and businesses.

Rubin is a big name in the mobile world. He is a cofounder of Android, which Google bought in 2005 and turned into Apple’s biggest mobile competitor and the most-used mobile operating system.

Google did not say why Rubin was replaced. Despite Android’s success, it is at a crossroads as device-making partners such as Samsung and Amazon have increasingly become competitors.