NEW YORK (CNN/Money) - Shares of Altria fell another 4 percent Friday afternoon, giving the stock a dividend yield of about 9 percent, as the company's cigarette unit suffered one more setback in its efforts to avoid posting a $12 billion bond.

The losses come after a panel of Illinois lawmakers voted down a proposal Thursday to permit Altria's Philip Morris unit to post a fraction of the $12 billion bond required before the cigarette maker appeals a verdict in a case over deceptive ads about smoking.

Altria, which also own a majority stake in Kraft Foods, may still be able to avoid the payment that it says will harm it financially. But investors were unnerved. Shares of Altria (MO: Research, Estimates) sank $1.31, or 4 percent, to $28.39.

That's still above the two-and-a-half year low below $28 hit Monday, but the stock is down some 50 percent from its 52-week high hit last summer.

The Illinois Circuit Court last month called for Altria's Philip Morris USA unit to pay $10.1 billion in a case in which it found that the company deceived smokers into thinking light cigarettes were safer than regular, full-flavored cigarettes. A judge ordered that the $12 billion bond be posted before the company could appeal.

Standard & Poor's responded by threatening to cut Altria's debt rating to junk bond status, which would make it much more expensive for Philip Morris to borrow by issuing bonds. Another rating agency, Moody's Investors Service, cut the company's credit rating by two notches this week.

The Thursday decision by Illinois lawmakers, if it stands, may come back to haunt the states that have sold bonds backed by a separate cigarette settlement with Altria.

Altria has said that "because of the extraordinary amount" of the bond required for appeal in the Illinois case, it may be unable to make a required $2.5 billion payment on April 15 that resulted from a settlement with states.

Philip Morris spokesman Brendan McCormick said, "We will continue to work to pass legislation that more adequately addresses our most significant concerns, one of which is a more reasonable cap."

The company, he said, wants it arguments to be heard on appeal without being hurt by the financial hardship of the $12 billion.

Martin Feldman, a tobacco industry analyst at Merrill Lynch, said the company may pursue an appeal of the case or the amount of the bond with the courts, or come to an agreement with the plaintiffs' attorneys to reduce the size of the bond.

A $12 billion payment would amount to about 20 percent of Altria's 2002 revenue, which was $62 billion.

Investors have historically flocked to Altria for its generous dividend. The company's latest quarterly dividend of 64 cents a common share, or $2.56 a year, gives Altria stock a yield of 8.9 percent.  

-- Reuters contributed to this report