Rush Limbaugh offered more contrition Monday for his comments about a Georgetown law student, but the conservative radio talk-show host continued to lose advertisers as a result of outrage over his characterization of the woman as a “slut” and a “prostitute.”

“Those two words were inappropriate and uncalled for,” Limbaugh said at the start of his show on Monday, referring to Sandra Fluke, a student who had spoken out in behalf of insurance coverage for contraception. “They distracted from the point I was actually trying to make and again I sincerely apologize to Ms. Fluke for using those two words.”

The apology reinforced a statement Limbaugh posted on his Web site Saturday in which he said that his “choice of words was not the best” and that he was attempting to be humorous in his attack on Fluke on two programs last week.

Many thought Limbaugh’s initial apology was inadequate, and their outrage helped compel advertisers to pull their commercials from Limbaugh’s program.

Two more national advertisers — online giant AOL and tax service Tax Resolution — said Monday that they were suspending their sponsorship of Limbaugh, bringing the total number of companies fleeing Limbaugh to nine. In addition, two local advertisers, Hadeed Carpet and Rug and window-replacement company Thompson Creek said they have pulled their ads from WMAL AM-FM, which airs Limbaugh’s show in the Washington area.

Whether Limbaugh’s on-air apology will stanch further losses remains unclear. A boycott campaign on Twitter and online petitions urging sponsors to remove their ads continued to draw supporters Monday.

Despite saying his apology was “heartfelt,” Limbaugh quickly pivoted to criticizing his opponents. “In fighting [liberals] on this issue, I became like them,” he said. He later added: “Don’t be mad at them, that’s what they do. Everyone was true to [their tactics] except me. I had one failing and that is why I sincerely apologized” to Fluke.

He also said he was unconcerned about the loss of advertisers: “They decided they don’t want you or your business anymore. . . . We’ll replace them.”

So far, only two of the 600 or so stations that air Limbaugh’s program have announced that they are dropping him: one in Hawaii, another in Massachusetts. The controversy — one of several that Limbaugh has been involved in during more than two decades on the air — might even temporarily boost his audience, as curious nonlisteners join his loyal supporters, known as “dittoheads.”

“The calls we’ve gotten today were from people concerned that we might take him off the air,” said Bobby Irwin, the operations manager of KVOR-AM, a station in Colorado Springs, Colo.

Limbaugh’s network of affiliated stations has every incentive to stay loyal. His three-hour weekday program is the most popular draw for these stations, most of which are on the AM band and receive the program for no cost.

According to the agreement stations sign, Limbaugh’s syndicator, Premiere Networks, is entitled to air national commercials during four minutes of each hour of Limbaugh’s program. Local stations have 16 minutes and 10 seconds of each hour for news updates and local commercials, or some 481 / 2 minutes over the course of the show. That makes Limbaugh highly valuable to station owners.

Fluke, appearing Monday on the ABC program “The View,” said Americans had to decide whether to support companies that advertise on his program. She said Limbaugh has not tried to contact her directly to apologize.

Among those condemning Limbaugh on Monday was radio host Don Imus, who lost his radio and TV jobs in 2007 for making insulting remarks about a women’s college basketball team.

Said Imus on his morning program: “He owns a Gulfstream 4. Get on it, go to Washington, take her to lunch and say, ‘Look, I’m sorry I said this stuff,’ and never do it again, period. Now, he’s an insincere pig, pill-popping pinhead.”