(By Mayur Pahilajani - iStockAnalyst Writer)  New York, NY - Worldwide markets are avidly following the news that Citigroup Inc. (NYSE: C) may be facing a possible merger or sale.  Although the company was once the US's fourth largest, it's market value has fallen to less than half in Wall Street's last four trading sessions.

Citigroup's board members are expected to meet today in the firm's New York headquarters to discuss future options for the company as Chief Executive Officer Vikram Pandit failed to restore investor confidence. Pandit has been trying to raise capital as the company reported net losses of more than $20 billion over the last four quarters.

The stock of the company have been battered since the start of the on-going financial turmoil and slumping credit market condition last summer, but the company was hit hard in recent days as concerns about the giant bank's future increased.

Financial turmoil has erased more than $33 trillion of value of shares in global markets so far this year, dragging the U.S., U.K., Germany and Japan deep into recession.

On Thursday, shares of the company plunged to a 15-year low, closing down by $1.69 or 26.41 percent to $4.71, hitting a 52-week low of $4.39. On Wednesday, stock sharply fell by 23 percent.

Citigroup also failed to raise investor confidence on reports that Saudi Arabian investor Prince Alwaleed bin Talal bin Abdulaziz Al Saud will be raising its stake in the firm back to 5 percent. He plans to invest around $349.0 million, which is based on Wednesday's closing price of $6.40, citing that shares of Citigroup are "dramatically undervalued."

The company added more losses after the collapse of Lehman Brothers Holding Inc. In the filing made by Lehman Brothers in the U.S. Bankruptcy Court in the Southern District of New York, Citigroup was listed as one of the biggest unsecured creditors with around $138 billion in bonds as of July 2.

In the third quarter, Citi reported third quarter net loss of $2.8 billion or 60 cents per share, reflecting $4.4 billion in write-downs in Securities and Banking segment for the third consecutive quarter. The bank also said it recorded $4.9 billion in net credit losses, and a $3.9 billion net charge to increase loan loss reserves.

The New York-based financial services firm has raised as much as $75 billion in new capital from sovereign wealth funds, the U.S. government and private investors. The government infused as much as $25 billion under the Troubled Asset Relief Program (TARP).

Recently, the firm decided to slash as many as 52,000 jobs in "near term" and to significantly reduce risky assets by selling them as the banking giant tries to shore up its finances and preserve its capital base. The company has set a new target for its workforce of around 300,000, compared to 352,000 at the end of September.

Citigroup also expects to shrink its expenses by almost 20 percent from its peak to range between $50 billion and $52 billion as it enters a new year. Shares of the company were trading higher by 29 cents or 6.16 percent to $5.00 in pre-market trading on Friday.