Saudi Prince Alwaleed isn't the only foreign investor giving a vote of confidence to struggling Citigroup (NYSE: C). Mexican-based Inbursa bank, controlled by billionaire Carlos Slim Helu, recently took a significant stake in the company, spending about $150 million to buy 29 million Citigroup shares, according to published reports.

Citigroup's stock price had been under significant pressure in recent weeks, which was later exacerbated when it announced that it would cut 53,000 jobs. Last week, shares dropped below $5 for the first time since 1994. But late Sunday, the government announced that it would give the bank an additional $20 billion and would absorb up to $300 billion in potential losses, a model some experts should be used to deal with other struggling institutions. The move also seems to be sitting well with investors including Slim, marked by a 60% jump earlier this week.

But Citi isn't the only company that Slim, one of the richest men in the world, has had his eyes on. Regulatory filings show that he recently boosted his stake in luxury retailer Saks (NYSE: SKS), buying nearly 7.6 million shares of the company over a four-day period. Saks is one of many luxury retailers suffering during the economic turmoil as even the rich cut down on spending. But with Slim's move, he is now the company's largest shareholder.