Futures for the Dow Jones industrial average, the Nasdaq 100 and the S&P 500 share indexes are down 1.3-1.7 percent, pointing to a sharply lower start on Wall Street.

* U.S. regulators have told Bank of America Corp and Citigroup Inc they may need to raise more capital following stress testing of the two banks, the Wall Street Journal reported.

The shortfall amounts to billions of dollars at BofA, the paper said on Tuesday, citing people familiar with the bank, adding it is likely the Federal Reserve will have determined other banks might also need more capital.

Frankfurt-listed shares in Bank of America were down more than 8 percent, while Citigroup slipped 8.8 percent.

* Sun Microsystems is due to announce its results. The company is expected to report a loss of 18 cents per share, down from a breakeven result a year ago.

* Results from Pfizer
will show how heavily the strong dollar and economic downturn have weighed on revenues. Analysts expect the company to report earnings of 49 cents per share for the quarter, down from 61 cents per share in the year-ago quarter.

* The Federal Open Market Committee begins its two-day meeting on interest rate policy.

* Bristol-Myers Squibb reports first-quarter results. Analysts see the company reporting a five cent-per-share rise in profit to 47 cents per share from the same quarter a year ago.

* Dendreon's prostate cancer vaccine will be presented at the American Urological Association annual meeting in Chicago. Shares of the biotechnology company tripled earlier this month when it reported its Provenge vaccine improved survival in the Phase III trial.

* Top refiner Valero Energy is due to announce results. The company is seen reporting a rise in earnings to 49 cents per share for the quarter, up from 36 cents in the same quarter a year ago.

* Coca-Cola Enterprises , the largest bottler of Coca-Cola drinks, reports first-quarter earnings, the week after Coca-Cola Co, its largest supplier, reported that its North American sales volume fell 2 percent in the quarter.

* Apparel maker VF Corp , home to more than 30 brands including Vans, Wrangler and The North Face, reports results. The company is expected to report earnings of 94 cents per share, down from $1.33 per share in the first quarter of 2007.

* At 1145 GMT, ICSC/Goldman Sachs to release chain store sales for the week ended April 25 versus the prior week. In the previous week, sales fell 0.4 percent.

* Redbook releases at 1255 GMT its Retail Sales Index of department and chain store sales for April versus March. In the prior period, sales rose 1.5 percent.

* The Conference Board releases April consumer Confidence, due at 1400 GMT. Economists in a Reuters survey expect a reading of 29.8 compared with 26.0 in March.

* European stocks tumbled on Tuesday, reversing a two-session rally, hit by growing fears about the economic impact of the swine flu outbreak and renewed concerns over capital increases in the banking sector.

The FTSEurofirst 300 <.FTEU3> index of top European shares was down 2.2 percent at 795.85 points.

(Reporting by Atul Prakash; editing by Mike Nesbit)