WASHINGTON: After days of secret talks, Senate Democrats tentatively agreed late on Tuesday night to drop a full-blown government-run insurance option from sweeping health care legislation, several officials said, a concession to party moderates whose votes are critical to passage of President Barack Obama's top domestic priority.

In its place, officials said Democrats had tentatively settled on a private insurance arrangement to be supervised by the federal agency that oversees the system through which lawmakers purchase coverage, with the possibility of greater government involvement if needed to ensure consumers of sufficient choices in coverage.

Additionally, the emerging agreement calls for the federal Medicare program for the elderly to be opened to uninsured Americans beginning at age 55, a significant expansion of the large government health care program that currently serves the 65-and-over population.