The following is a timeline of events in DP World's proposed $6.8 billion takeover of major operations at six U.S. ports:

Oct. 17, 2005 — Representatives of DP World approach Treasury officials about its plans to purchase the British firm, Peninsular and Oriental Steam Navigation Co., which controls major operations at six U.S. ports.

Nov. 2 — Homeland Security Department asks U.S. intelligence agencies for information on DP World; they produce nothing "derogatory," according to DHS officials.

Dec. 6 — Staff from all agencies who sit on the U.S. Committee on Foreign Investment (CFIUS) meet with company officials to review transaction.

Dec. 16 — Company files formal notice of deal with Treasury, which circulates the filing to all CFIUS departments and agencies, as well as the departments of Energy and Transportation.

Jan. 17, 2006 — CFIUS does not object to the transaction after a 30-day review in which Homeland Security gets DP World to agree to open its books and keep the current U.S. ports management intact.

Feb. 11 — The Associated Press reports the deal, including Dubai's ties to Sept. 11 terrorists.

Week of Feb. 13 — Lawmakers from both parties, including Democratic Sen. Charles Schumer and GOP Rep. John Sweeney, call on Treasury Secretary John Snow and Homeland Secretary Michael Chertoff to explain the deal publicly.

Feb. 16 — Aides inform President Bush of controversy and that administration had approved the deal a month earlier.

Feb. 20 — Senate Majority Leader Bill Frist says he will introduce legislation to delay the transaction if the White House doesn't do so.

Feb. 21 — Bush defends the deal, saying it "will not jeopardize the security of the country," and he vows to veto any congressional effort to stop it.

Feb. 23 — Senate Armed Services Committee holds hearing; Democrats charge Bush administration violated law by not conducting an additional 45-day security review and fully informing Congress. DP World later suggests it will delay the transaction to give lawmakers time to be briefed fully.

Feb. 26 — DP World agrees to a 45-day review and promises to create a U.S. subsidiary that would operate independently of executives in Dubai until May.