US STOCKS-Futures retreat as growth concerns weigh
* AstraZeneca rejects sweetened Pfizer offer
* AT&T to buy DirecTV for $48.5 billion
* Futures off: Dow 33 pts, S&P 4.5 pts, Nasdaq 7.75 pts
By Chuck Mikolajczak
NEW YORK, May 19 (Reuters) - U.S. stock index futures fell on Monday, on the heels of back-to-back weekly declines for the S&P 500 as investors grew cautious over stock valuations with indexes near record levels amid mixed economic data.
* U.S. listed shares of AstraZeneca slumped 11.6 percent to $71 in premarket trade after the British drugmaker rejected a sweetened and "final" merger offer from Pfizer which would have created the world's largest pharmaceuticals group. Pfizer shares advanced 2.2 percent to $29.77 before the opening bell.
* AT&T lost 2.1 percent to $35.95 in premarket trade after the telecom said it will acquire DirecTV for $48.5 billion, highlighting AT&T's pressing need for fresh avenues of growth beyond the maturing U.S. cellular business. DirecTV shares edged up 0.1 percent to $86.25 in premarket.
* Equities have come under pressure recently, with consecutive weekly declines for the first time since January as investors have become leery of growth prospects as a result of mixed economic data. Continuación...