French pharmaceutical firm Sanofi said Monday it had reached an agreement to purchase US biotech company Bioverativ, which specialises in treatments for haemophilia and rare blood disorders, for $11.6 billion (9.5 billion euros).

Sanofi's chief executive Olivier Brandicourt said the acquisition "enhances its presence in specialty care and leadership in rare diseases ... and creates a platform for growth in other rare blood disorders."

The purchase should also translate into a boost in profits per share beginning this year, rising to a gain of up to 5 percent in 2019, Sanofi said in a statement.

But investors were not convinced, sending Sanofi's shares sharply lower in early business on the Paris stock exchange.

Bioverativ has latest-generation treatments for haemophilia, a disorder where blood does not clot properly to stop bleeding.

Sanofi said it would be able to help Bioverativ with the research it has under way on the development of other haemophilia treatments as well as for other rare diseases.

The agreement to purchase all of Bioverativ's outstanding shares for $105 each in cash represents a premium of 64 percent from the closing price on Friday, Sanofi said.

The French firm said it would use funds on hand and borrow to finance the acquisition of Bioverativ.

The purchase is the largest Sanofi has made since it acquired US biotech firm Genzyme for $20 billion in April 2011.

Sanofi shares were three percent lower at 70.74 euros around 40 minutes into Monday's trading, vastly underperforming the benchmark CAC 40 index in Paris which was down 0.1 percent.

Source: AFP