Washington - Barack Obama signed his first piece of legislation as US president on Thursday, approving a bill that gives workers more time to file complaints for wage discrimination.

"This is a wonderful day," Obama said before signing the Lilly Ledbetter Fair Pay Restoration Act, which is named after a female factory manager at Goodyear who discovered she had been paid less than her male colleagues for two decades.

Ledbetter was refused compensation in 2007 by the US Supreme Court, which ruled that workers could only begin court action within
180 days of the start of the discrimination.

The legislation, approved by the US Senate last week and the House of Representatives on Tuesday, allows a worker to log a complaint for every new salary cheque they receive that continues the discrimination.

"I sign this bill for my daughters and all those who will come after us," Obama said in a signing ceremony in the White House East Room.

"Equal pay isn't just an economic issue for millions of Americans and their families, it's a question of who we are ... whether we're truly living up to our fundamental ideals," Obama said. (dpa)