Now that it's betting $12.5 billion to acquire Motorola Mobility, Google plans to unveil its latest version of the Android OS, known as Ice Cream Sandwich, at a Hong Kong event Wednesday with Samsung Electronics.

If market forecasters are correct, the new Google OS will likely be the world's most popular for smartphones and tablets not made by arch-rival Apple, which has reported record downloads for its competing iOS 5 for all devices as well as 4 million new iPhone 4S units shipped since Friday.

Indeed, Google and Samsung postponed the Ice Cream Sandwich introduction because it was originally intended for Oct. 11, six days after the death of Apple Chairman Steve Jobs.

Strategically, the new Google OS is crucial for the company because for the first time, like iOS 5, it will be a universal system for all portable platforms, offer a more user-friendly interface and have better compatibility with mice, keyboards and game controllers.

To date, Mountain View, Calif.-based Google has used one version of Android on smartphones and the newer version 3.0 Honeycomb on tablets, so releasing Ice Cream Sandwich, likely to be formally dubbed Android OS 4, will solve a major problem.

Google Android-based smartphones commanded more than 55 percent of the market in the second quarter, estimates IHSiSuppli, while Apple's iPhones were about 19 percent. In tablets, though, Apple's iPad line had about a 75 percent market share, IHSiSuppli said.

The two leaders compete against the rapidly falling Symbian OS used in Europe, Microsoft's Tablet 8 OS and BlackBerry developer Research in Motion's OS and forthcoming QNX OS for PlayBook tablets. RIM executives are expected to provide more information about that product during their developers conference this week.

By next quarter, Google itself plans to conclude the Motorola Mobility acquisition, so it will itself be one of the world's biggest smartphone developers. In the second quarter, Motorola accounted for about 4 percent of global smartphone shipments, IHSiSuppli estimates.

But Motorola Mobility late Tuesday is expected to begin pre-orders for its latest Droid Razr phone, sold with a 4.5-ibnch display, dual-core 1.2 GHz processing power, 1GB of RAM and an 8 MP camera. By late Tuesday in the U.S., Google and Samsung's Hong Kong event will begin, anyway.

By showcasing Ice Cream Sandwich with Korea's Samsung, Google also will promote one of the fastest-growing smartphone developers as well as a bitter rival of Apple, to which it is a major supplier of components and electronics. Apple and Samsung are in courts worldwide over alleged patent infringement as well as government agencies including the U.S. International Trade Commission and the European Commission.

Apple, based in Cupertino, Calif., has used as the basis for its lawsuits the claim that Samsung has slavishly copied its iPhone designs. Samsung has denied that.

In the second quarter, Samsung's share of the smartphone market was 17.8 percent, only slightly behind Apple. The Korean maker has also won strong initial sales for the Galaxy Tab S in world markets.

Dubbing the latest Android OS Ice Cream Sandwich maintains Google's practice of naming in-house releases after desserts. Earlier versions carried monickers including Cupcake, Donut, Éclair, Froyo and Gingerbread.

Google shares traded around $584.50, up $2.09, in early Tuesday trading, while Motorola Mobility was at $39.87, up 5 cents. Apple, scheduled to report fourth-quarter results after the close, was at $419.51, down 41 cents.