The pharmaceutical giant was the worst performer among OMXS30 companies, falling 9.4 percent, after reports to the Financial Times of a merger with American competitor Bristol Myers Squibb.
Among large companies, defence group Saab performed particularly well, up 2.9 percent. Venture capital company EQT also performed strongly, up 2.8 percent.
The general rise on the Stockholm Stock Exchange was in line with developments across Europe. On Monday, oil prices fell by around 4.6 percent amid renewed optimism about a solution to the Iran conflict. President Donald Trump said that new talks would begin on Monday.
