Makers of hit US television series "Desperate Housewives" have apologized for a slur against Filipino medical workers that caused an uproar in the Southeast Asian country.

The apology was sent to Philippine broadcaster ABS-CBN's bureau in the United States and aired in the Philippines on Thursday following protests by the Manila government.

"The producers of 'Desperate Housewives' and ABC Studios offer our sincere apologies for any offense caused by the brief reference in the season premiere," cable news channnel ANC quoted the statement as saying.

"There was no intent to disparage the integrity of any aspect of the medical community in the Philippines," it said.

The episode showed actress Teri Hatcher, who plays Susan Mayer, asking during a medical consultation to check "those diplomas because I want to make sure that they're not from some med school in the Philippines."

The apology was made a day after chief aide to Philippine President Gloria Arroyo said the line of dialogue appeared to be a "racial slur."

Philippine Senators said the apology was not enough, and urged their Foreign Affairs Department to lodge a formal protest with the US government.

"I am mortally offended by the statement because it betrayed the racial prejudice and denigrates the excellent performance of world-class Filipino doctors in the US," said Senator Miriam Santiago, whose sister is a doctor working in Los Angeles.