Citigroup is reportedly considering a merger with financial institutions Goldman Sachs or Morgan Stanley, according to a CNBC report.

Citigroup's stock is rising in after hours trading, up $0.26 to $4.97, but earlier today the stock closed down sharply, losing 26.41%.

According to the report, Citigroup is considering a merger or seeking a new investor.

A Wall Street Journal report, citing sources familiar with the matter, said Thursday night Citigroup is in the early stages of debate over a potential merger, and will meet Friday to continue discussions.

The report said the company may also opt to sell parts of itself, like its credit card business, but that CEO Vikram Pandit doesn't think this is the best line of action. Morgan Stanley has not spoken to Citigroup regarding a merger recently, the report said.

The Wall Street Journal report also said top executives at Citigroup are frustrated and puzzled by the stock's 50% slide this week.

By Megan Ainscow
©CEP News Ltd. 2008