US Stock Markets

* Rite Aid (RAD.N) rose 4.9 percent to $7.95 in premarket after the drugstore operator said it would buy privately held pharmacy benefit manager EnvisionRx for about $2 billion.

* Pier 1 Imports (PIR.N) tumbled 31.4 percent to $11.65 in premarket after the furniture retailer cut its 2015 profit forecast, citing weak sales in January and February.

* After the closing bell, earnings are expected from Applied Materials (AMAT.O), Cisco Systems (CSCO.O), TripAdvisor (TRIP.O) and Whole Foods Market (WFM.O)

* European shares slipped, with investors uneasy over the euro zone ministerial meetings on Greece's debt crisis while Asian markets edged lower with Japanese markets closed for a public holiday.

Futures snapshot at 7:33:

* S&P 500 e-minis ESc1 were down 1.75 points, or 0.08 percent, with 68,252 contracts changing hands.

* Nasdaq 100 e-minis NQc1 remained unchanged, in volume of 10,712 contracts.

* Dow e-minis 1YMc1 were down 24 points, or 0.13 percent, with 9,611 contracts changing hands.