(Sharecast News) - Standard&Poor's placed its rating on AstraZeneca's long-term corporate debt on so-called Credit Watch Positive following news of its intended purchase of US rare disease specialist Alexion.
The ratings agency said that the purchase, which carried a price tag of approximately $40bn, "will increase AZ's penetration in the expanding rare disease franchise and support above-average profitability."
Furthermore, the "conservative" financing package for the transaction would allow the British pharmaceutical giant to continue on its path towards deleveraging, S&P added.
S&P also said that its intention was to raise the firm's long-term issuer credit rating from BBB+ to A- upon transaction close "assuming that more than 50% of the acquisition costs are financed by shareholders."
The rating on AstraZeneca's commercial paper meanwhile was affirmed at A-2.
As of 1526 GMT, stock in AstraZeneca was up 1.83% at 7,642.0p.