Updated

President Obama signed his first bill on Thursday, an equal-pay measure that makes it easier for workers to sue for discrimination on the job.

The Lilly Ledbetter Fair Pay Act extends the period an employee can file a claim of discrimination for making less money than another worker doing the same job.

At a White House bill-signing ceremony, Obama said the measure sends a clear message that making economy the economy work means making it work for everyone.

It sends the message "that there are no second class citizens in our workplaces, and that it's not just unfair and illegal -- but bad for business-- to pay someone less because of their gender, age, race, ethnicity, religion or disability," he said before a packed East Room audience.

This is more than just a women's issue, Obama said.

"It's about parents who find themselves with less money for tuition or child care; couples who wind up with less to retire on; households where, when one breadwinner is paid less than she deserves, that's the difference between affording the mortgage or not; between keeping the heat on, or paying the doctor's bills or not," he said.

The bill is named for a woman who said she didn't become aware of a pay discrepancy until she neared the end of her career at a plant owned by Ohio-based Goodyear Tire & Rubber Co..

Ledbetter attended the ceremony Thursday, along with House Speaker Nancy Pelosi, the first woman speaker in the history of Congress, and Secretary of State Hillary Clinton. Clinton went further than any woman previously in her campaign for the presidency, although she ultimately lost the Democratic Part competition to Obama.

After the signing, first lady Michelle Obama hosted a reception in the State Dining Room.

Ledbetter became a regular feature in Obama's campaign for the White House, addressing the Democratic National Convention in Denver last year and traveling to Washington aboard Obama's train for the inauguration ceremonies.

The measure, which amends the 1964 Civil Rights Act, also applies to discrimination based on factors such as race, religion, national origin, disability or age.

The act will effectively overturn a 2007 Supreme Court decision on the Ledbetter case that said workers had only 180 days to file a pay-discrimination lawsuit.

Under the new bill every new discriminatory paycheck extends the statute of limitation for a second 180 days.

The bill does not change current law limiting back pay for claimants to two years.

The Associated Press contributed to this report.