AstraZeneca has agreed to buy U.S. biotech company Ardea Biosciences for $1.26 billion (782 million pounds), giving it access to a new drug for treating gout patients in the latest deal to try and bolster its weak drug pipeline.

Net of the existing cash that is held by Ardea, the acquisition - at $32 a share - is valued at $1 billion, the companies said on Monday.

AstraZeneca is facing competition from cheap generic versions of several key drugs, including its big-selling antipsychotic Seroquel, at a time when its own pipeline of new medicines is relatively barren.

Earlier this month Britain's second-biggest drugmaker also signed a collaboration deal to jointly develop and sell five biotech drugs currently in Amgen's developmental pipeline.

(Reporting by Ben Hirschler)