Google is gearing up for a major effort to spur development of premium Android smartphones and re-assert control over the Android ecosystem as it seeks to better compete with the Apple iPhone and blunt the growing power of Samsung, the leading maker of Android phones.

The expensive effort involves dumping the four-year-old Google Nexus phone brand in favor of a new program called Silver, under which manufacturers and wireless carriers will effectively be paid to produce and sell high-end devices that closely adhere to Google specifications, according to four people briefed on the project. The requirements sharply limit the number of non-Google apps that can be pre-installed on devices, or mandate that phone owners be able to uninstall them. [An update on the Nexus program, which is continuing, can be found here. An update on Android Silver, which is being shut down, is here.]