Citigroup is expected to announce a series of drastic steps on Tuesday, including the elimination at least 4,000 additional jobs, a steep cut in its stock dividend and another big investment by foreign investors, in a bid to bolster its finances in the face of deepening losses.

Beginning what is expected to be a grim week for financial company earnings, Citigroup is likely to announce a write-down of $18 billion to $20 billion, the biggest yet by a major bank or Wall Street firm, said a person briefed on the situation. Such a big loss, the result of soured mortgage-related investments, could wipe out the bank’s profit for all of 2007 and plunge it into the red.

As part of a plan to shore up Citigroup, the chief executive, Vikram S. Pandit, is expected to announce the start of a new round of job cuts that many analysts say will accelerate in the coming months. The first reductions, of about 4,000 workers, will come on top of 17,000 job cuts announced last spring.

Citigroup is also expected to turn to wealthy foreign governments again and announce the sale of a $12.5 billion stake to the Kuwait Investment Authority and several others, including Prince Walid bin Talal of Saudi Arabia, people briefed on the situation said. In November, the company sold a $7.5 billion stake to a Middle Eastern fund, the Abu Dhabi Investment Authority.