Nov. 19 (Bloomberg) -- Frances Fragos Townsend, who announced today she's leaving her job as White House homeland security adviser, said the U.S. must be on guard against the threat of a terrorist attack tied to next year's elections.

Before she leaves President George W. Bush's administration in early 2008, Townsend said she wants to make sure that plans are in place to head off any potential terrorist threat before or after elections for president and Congress and to ensure there is ``no lag in information sharing'' between the Bush administration and the next occupant of the White House.

``We know that al-Qaeda'' tends to view elections ``as a period of vulnerability,'' Townsend, 45, said in an interview. ``I don't know if there will be a particular threat, but we can't ignore what we have already seen.''

Townsend, Bush's homeland security adviser since 2003, said al-Qaeda has established a pattern in previous attacks against U.S. allies. Members of the terrorist network carried out bombings in Madrid and Glasgow when Spain and Britain were facing elections and a transfer of power.

The president hasn't named a replacement for Townsend. Bush earlier today said in a statement that she ``has played an integral role in the formation of key strategies and policies my administration has used to combat terror and protect Americans.''

Intelligence Sharing

An important goal for the next Homeland Security director, she said, will be continuing to improve the sharing of intelligence among federal, state and local government agencies.

One of the biggest disappointments from her tenure, she said, is that the administration hasn't captured or killed al- Qaeda leader Osama bin Laden.

``I'm absolutely confident we will ultimately be successful,'' she said. ``But would I like to be standing here announcing that he's dead? Absolutely.''

Townsend said she plans to pursue a job in the private sector, because many of the skills she has developed in government can be applied to protecting private companies. ``I assess vulnerability and gaps, and assess how to minimize consequences of events,'' she said.

A former assistant district attorney in Brooklyn and assistant U.S. attorney in Manhattan, Townsend said she plans to return to New York and would consider running for public office in the future. ``You never know,'' she said.

Naming a Successor

Bush spokeswoman Dana Perino said the president wants to name Townsend's successor ``relatively soon.'' Townsend is planning to leave shortly after the start of the new year. Perino said the administration is ``confident'' Bush will be able to recruit a top candidate even with only 15 months left in his term.

Bush leaves office in January 2009 and Townsend's resignation fits within a trend of long-time aides departing the administration. Since last year's elections, when Democrats won majorities in Congress, those who have left include Bush's top political adviser Karl Rove, counselor Dan Bartlett, Attorney General Alberto Gonzales, chief White House attorney Harriet Miers, budget chief Rob Portman, political director Sara Taylor, deputy national security adviser J.D. Crouch and Meghan O'Sullivan, a deputy national security adviser who worked on Iraq.

To contact the reporter on this story: Holly Rosenkrantz in Washington at hrosenkrantz@bloomberg.net

Last Updated: November 19, 2007 16:24 EST