UPDATE 1-FACTBOX-Key elements of U.S. Congress' bailout plan

(Adds further detail from draft bill)

Sept 28 (Reuters) - Leaders in the U.S. Congress have agreed to the underpinnings of a deal that will allow the Treasury Department to buy up to $700 billion in troubled securities to soothe global credit markets.

In recent days, congressional negotiators amended the Treasury Department's original proposal to add new oversight powers and conditions that would protect taxpayers.

Early Sunday, congressional leaders announced they had reached agreement on key elements of the plan and that staff were writing the final language. The full House of Representatives and Senate must both ratify the legislation.

Below are key elements of the rescue plan as explained by lawmakers and early drafts of the legislation:

- The $700 billion in buying power would be doled out by Congress in stages. After the first $250 billion is authorized, the President could request another $100 billion. The final $350 billion could be cleared by a further act of Congress.

- The government will take a stake in companies that tap federal aid so that taxpayers can share in the profits if those companies get back on their feet. An exception applies to financial firms with less than $500 million in assets or if the government buys less than $100 million of soured investments.

- If a company receives aid but fails, the government will be one of the last investors to see a loss.

- A new congressional panel would have oversight power and the Treasury secretary would report regularly to lawmakers in two elements of a multi-level oversight apparatus.

- If the Treasury takes a stake in a company, the top five executives would be subject to limits on their compensation.

- Executives hired after a financial company offloads more than $300 million in assets will not eligible for "golden parachutes."

- Would permit the Federal Reserve to begin paying interest on bank reserves, giving it another tool for easing credit strains.

- Mandates a study on the impact of mark-to-market accounting standards, that critics blame for a downward spiral in the valuation of assets on corporate balance sheets.

- The federal government may stall foreclosure proceedings on home loans purchased under the plan.

- Alongside the plan to buy securities outright, the Treasury Department will conceive an alternative insurance program that would underwrite troubled loans and would be paid for by participating companies.

- If the government has taken losses five years into the program, the Treasury Department will draft a plan to tax the companies that took part to recoup taxpayer losses. (Reporting by Patrick Rucker; Editing by Tim Dobbyn)