Warren Buffett is probably the most closely followed investor in the world, and for good reason. Since 1960, Buffett's Berkshire Hathaway (NYSE:BRK-A) (NYSE:BRK-B) has delivered outstanding returns year after year.

Most people focus only on what companies Buffett is buying now, or speculate about what he may buy in the future. However, the Oracle of Omaha also sells some of his holdings on occasion, so we asked three of our analysts which Buffett stock may be the next to go.

Leo Sun: Berkshire Hathaway owns nearly 10% of Chicago Bridge & Iron (NYSE:CBI), an energy infrastructure company that lost nearly half its market value over the past 12 months. CB&I builds liquefied natural gas terminals, petrochemical processing plants, storage tanks, and other infrastructure.

Berkshire's average purchase price for CB&I is unclear, but filings from state insurance regulators (as reported by Bloomberg) show that it started its position for around $55 per share in 2013. Berkshire added 1.7 million shares for an average price of $70.34 per share last year.

Adding shares was an interesting move, since Berkshire did so after short seller Prescience Point Research Group claimed that the stock -- then trading in the $70 range -- was worth only $37 per share. Prescience Point claimed that CB&I's acquisition of Shaw Group in 2013, which expanded its footprint into nuclear power, produced financial statements "divorced from economic realities." CB&I CEO Philip Asherman claimed that Prescience Point made "erroneous claims," but short sellers hammered the stock to the low $40 range.

Buffett seldom gets spooked by short sellers, but CB&I faces challenges as declining commodity prices throttle the ability of energy companies to expand their infrastructure, so Berkshire might reduce its stake in CB&I in 2015. However, CB&I still has plenty of strengths -- last quarter, revenue rose 13% year over year as earnings soared 37%, and recovering energy prices could help the stock eventually recover.

Selena Maranjian: If you're looking at a list of Berkshire Hathaway's stock holdings and thinking about which stocks its CEO, Warren Buffett, might sell, you should know two things first. For starters, he's not the only one making investment decisions at Berkshire Hathaway, as he's complemented by two investing lieutenants, Ted Weschler and Todd Combs. Each was recently managing about $7 billion or more; thus, some holdings and purchases and sales don't reflect Buffett's thinking. Next, it's worth remembering that Buffett's favorite holding period is "forever." He is known for hanging on to key stock positions for decades when possible, through thick and thin. Therefore, it's hard to come up with stocks he'd sell.

If he were more of a seller, though, one holding that might be shown the door is Coca-Cola (NYSE:KO). Buffett first started buying his hefty position (9.1% of the company!) back in 1988, and according to my Foolish colleague Anders Bylund, "His original investment has soared to a 1,580% return -- or 2,840% when accounting for dividends.") But times have changed. Few would have foreseen it a decade or two ago, but soda consumption has been falling globally, while beverages such as tea, juices, energy drinks, and bottled water have been growing in beverage share. Soda sales even dropped in Mexico, the company's biggest market, in part because of a new tax aimed at curbing obesity.

I would never count Coca-Cola out, as it has deep pockets and the ability to turn things around. But as of now, it's far from the most appealing company around. Its revenue has been falling for the past few years, as has its net income. Gross margins are well below where they were a few years ago, and net margins recently hit their lowest point in more than a decade. Its growth prospects are challenged by the fact that its global saturation level is rather high, with its offerings quaffed in some 200-plus nations and territories. The company has been making investments in major alternative beverage companies such as Keurig Green Mountain (UNKNOWN:GMCR.DL), Monster Beverage (NASDAQ:MNST) and VitaminWater maker Glaceau, though some feel it has overpaid.

Dan Caplinger: Looking at all of Buffett's holdings, one that stands out as seeming increasingly out of place is French pharmaceutical company Sanofi (NASDAQ:SNY). With a dividend yield above 4%, Sanofi might appear to be a simple dividend-income play, and Buffett has also traditionally held a basket of pharma stocks rather than making a big bet that any one company will develop the next blockbuster drug. That offered diversification as the industry recovered from the financial crisis.

Yet Buffett has already made moves away from his pharma holdings, selling off shares of GlaxoSmithKline and trimming his positions in Sanofi slightly in 2013. He has also reduced his stake in U.S. healthcare giant Johnson & Johnson (NYSE:JNJ). Meanwhile, Buffett has built up his positions in dialysis-center operator DaVita Healthcare Partners, suggesting that his focus has shifted toward other areas of the healthcare space. With Sanofi's earnings having come under pressure recently, the company still faces some patent-cliff issues that could push profits down even further if the company can't replace lost sales with newer products. Given the speculative nature of some of Sanofi's best prospects going forward, investors shouldn't be disappointed if Buffett decides that he should sell his shares and look for better investments elsewhere.