President Barack Obama will sign an executive order on Monday barring federal contractors from discriminating on the basis of sexual orientation or gender identity, senior administration officials said, according to The Associated Press.

The White House said last month that Obama would issue the order but declined to give details on its content or the timing of when he would do so, the AP reported. The order will allow some exemptions for religious groups that are federal contractors but not as much flexibility as the groups had wanted.

A religious organization would be barred from making hiring decisions based on sexual orientation or gender identity, according to the AP. Exceptions would be allowed for ministers, and groups would be allowed to favor individuals of a particular religion when hiring.

Officials told reporters on Friday that Obama's action would update two previous orders about discrimination already on the books, the AP reported.

It would update an order by President Lyndon Johnson by adding sexual orientation and gender identity to a list of protected categories for federal contractors, according to the AP.

It would also update an order by President Richard Nixon from 1969, adding gender identity to a list of groups that are protected from being discriminated against as federal employees, the AP reported.

The order already banned discrimination on the basis of race, color, religion, sex, national origin, disability and age, according to the AP. It was updated in 1998 by President Bill Clinton to include sexual orientation.

A senior administration official said the order would affect 24,000 companies that employ some 28 million workers, roughly a fifth of the nation's work force, the AP reported. Obama has pressed Congress to pass legislation that would ban such discrimination for all companies, but it has failed to gain traction with Republican lawmakers.

The White House believes the order will help improve productivity by reducing fears among employees that they could be fired for being gay, lesbian, bisexual, or transgender, according to the AP.

"This is another case where doing what is right also helps businesses improve their bottom line," one official told reporters on a conference call, the AP reported.