Stock futures traded slightly above fair value in the early part of the pre-market session Tuesday but eventually closed flat. The futures action led to a relatively quiet open where stock prices hovered near the flat line for the opening minutes of the session.

After the wholesale inventories report for February the averages began to weaken. The selling accelerated in the last hour, pushing each of the major indices to session lows and down over 1%.

Near noon, the Dow was down 158.14, or 1.22%, to 12,771.45; the Nasdaq was down 44.90, or 1.47%, to 3,002.18; and the S&P 500 was down 19.25, or 1.39%, to 1,362.95.

Economic events
Domestically, the NFIB small business optimism index fell to 92.5 in March. U.S. wholesale inventories rose 0.9% in February, versus analysts' estimates of an increase of 0.5%. The Labor Department said employers posted 3.5 million job openings in February, up just barely from a revised 3.48 million in January.

Internationally, China reported an unexpected trade surplus in March, as imports rose 5.3% and exports increased 8.9% from a year earlier for a surplus of $5.35 billion. Also, Spain's borrowing costs rose again to hit their highest levels since December.

Company news
Best Buy (BBY) announced its CEO Brian Dunn resigned, citing a mutual agreement that new leadership was needed at the company. Shares spiked initially but then reversed to be down 3.5% near noon.

Sony (SNE) more than doubled its projected annual loss to $6.4 billion as it writes off deferred tax credits, sending its stock down over 10%.

Major movers
Among the notable gainers were X-Rite Incorporated (XRIT), up 39%, after Danaher (DHR) agreed to acquire the company for $5.55 per share, and SuperValu (SVU), up 9%, following quarterly adjusted earnings and guidance that beat estimates. Noteworthy losers included ViroPharma (VPHM), down 16.5%, after Akorn (AKRX), Watson (WPI) and a third company gained approval and launched generic versions of its Vancocin drug, and Optimer (OPTR), down about 10%, following a warning that first-quarter revenue will miss consensus.