AstraZeneca, Pfizer, Novartis courting Onyx

After Amgen ($AMGN) pulled the trigger on the bid for Onyx Pharmaceuticals ($ONXX), AstraZeneca ($AZN), Novartis ($NVS) and Pfizer ($PFE) also are reportedly vying for chance to scoop up the company in an acquisition, according to Bloomberg. The news wire reports that the four companies have signed confidentiality agreements and hired advisers, and could make first-round bids this week. Last week, Reuters reported that Pfizer had backed out of the running, citing the news wire's own sources. Story | More on Onyx buyout buzz