4. Saudi Aramco + Saudi Basic Industries Corporation
Sector: Industrials and chemicals
Deal value: $70.4 billion
Source: Mergermarket
3. AbbVie + Allergan
Tickers: AGN, ABBV
Sector: Pharmaceuticals
Deal value: $86.3 billion
Source: Mergermarket
2. United Technologies + Raytheon
Tickers: UTX, RTN
Sector: Defense
Deal value: $88.9 billion
Source: Mergermarket
1. Bristol-Myers Squibb + Celgene
Tickers: BMY, CELG
Sector: Pharmaceuticals
Deal value: $89.5 billion
Source: Mergermarket