Check out which companies are making headlines before the bell on Monday:
Berkshire Hathaway - Berkshire reported fourth-quarter profit of $1,704 per share, below Street estimates of $1,755, and Warren Buffett called the company's 2012 performance "subpar" in his annual letter to shareholders.
(Read More: Buffett Still Buying Stocks, Sees 'Good Value')
Transocean - Transocean reported fourth-quarter profit of $0.91 per share, excluding certain items, nine cents above estimates, with revenue essentially in line with consensus. The offshore drilling contractor saw its so-called revenue efficiency rise to 94.7 percent compared to 91.8 percent a year earlier.
Las Vegas Sands - Las Vegas Sands is disputing reports out late Friday that it likely violated the Foreign Corrupt Practices Act. The casino operator said that its audit committee found likely violations of accounting provisions, which could mean just a single or a handful of incorrectly recorded transactions. Las Vegas Sands is particularly upset with a New York Times headline that said "Casino Says It Likely Cheated," calling it uninformed and misleading reporting.