Washington - Sen. Edward Kennedy is introducing a major new national service bill aimed at recruiting 175,000 Americans of all ages to tackle national problems such as health care, education, energy and the environment.

    It is Kennedy's first major piece of legislation since being diagnosed with a malignant brain tumor in May. The 76-year-old senator has been working from his Hyannis Port, Mass., home on the "Serve America Act" with Republican Sen. Orrin Hatch of Utah, a longtime friend.

    Details of the legislation will be presented Friday at an event in New York City. Kennedy's niece, Caroline Kennedy, and Hatch are expected to attend. Aides said the Massachusetts senator did not plan to be at the event.

    "Time and again we've learned that large numbers of Americans are ready, willing, able, and even eager to be involved in service, and that all we have to do is ask them to do so," Kennedy, D-Mass., said in a statement. "The Serve America Act will ask. It will connect every generation through service, and enable them to help tackle a wide range of national challenges, from the dropout crisis that plagues our schools to the lack of health care in our neediest communities to the energy and environmental crises that threatens our planet."

    The Kennedy-Hatch bill would expand the number of national service participants to 250,000 and ask that they devote a year to some of the nation's most pressing challenges. The measure also seeks to expand opportunities for people to serve their communities at every stage of life, from students and working adults to retirees. Aging baby-boomers would be among those encouraged to perform community service.

    "America faces more challenges today than ever before," Hatch said in a statement. "And new challenges require a new level of commitment. By harnessing the talents and efforts of the American people, faith-based groups and nonprofit organizations, we can empower more people, improve more communities and tackle more of our nation's greatest challenges."

    The bill seeks to build on national service efforts begun under past presidents, including former President Kennedy.

    Kennedy, who is chairman of the Health, Education, Labor and Pensions Committee, in recent weeks has been laying the groundwork for a renewed push early next year on his signature issue, universal health care. He hopes to capitalize on any momentum that the next president carries into office, particularly if it is Democrat Barack Obama, an ally on health care.

    This summer Kennedy has also been working closely with his son, Rep. Patrick Kennedy, D-R.I., on a mental health parity bill requiring equal health insurance coverage for mental and physical illnesses.

    Kennedy was not on Capitol Hill this week as Congress returned from its summer break. He plans to work from his Massachusetts home this fall and return to the Senate in January.

    At the Democratic National Convention in Denver, Kennedy made a surprise appearance for a speech that drew a rousing response from delegates. He made the appearance despite suffering from a bout of kidney stones. Kennedy has been one of Democratic presidential nominee Barack Obama's strongest supporters.

    In July, Kennedy made a surprise visit to the Senate to cast an important Medicare vote.