After an $18.9 billion loss in the third quarter, Fannie Mae plans to dip into an emergency Treasury Department fund for the fourth time this year, the Securities and Exchange Commission said yesterday. On top of the $44.9 billion the government-sponsored mortgage giant has already received in emergency financing, the company will ask for an additional $15 billion. The company says it does not foresee a quick end to its losses, and many believe this will not be the last time Fannie Mae will need to be bailed out. Ultimately, Fannie Mae will likely rack up $200 billion in emergency government funds, said Paul Miller, an analyst at Arlington, Va.-based FBR Capital Markets. Shares of Fannie Mae closed at $1.12 yesterday. They peaked at $87.81 in December 2000.