Filed under: Before the bell, Earnings reports, Deals, Contl Airlines’B’ (CAL), Economic data, Delta Air Lines (DAL)

U.S. stock futures were down slightly this morning, reflecting nervousness about economic data and earnings reports due out this day.

Stocks fell Tuesday for the second session in a row after disappointing earnings from Wachovia surprised the market. The Dow industrials ended the day down 23 points, the S&P 500 lost 5 points, and the Nasdaq Composite fell by 14 points.

In the news, Delta Air Lines (NYSE: DAL) and Northwest Airlines (NYSE: NWA) announced yesterday that they will combine to form the world’s largest airline, with a market value of $17.7 billion. The new airline will be called Delta. United and Continental may be next in line to tie the knot.

In another blow to the ailing airline sector, oil prices rose to an intraday record of more than $112 a barrel Tuesday as the U.S. dollar continued to weaken against other major currencies.

There was evidence of continuing deterioration in the housing market — according to a report by RealtyTrac for March, U.S. foreclosure filings rose 57% and bank repossessions more than doubled from last year. However, there was some good news from Detroit as Ford announces plans to step up production of the compact Focus by 30% to meet strong demand.

Economic data due out this day includes the Producer Price Index, a measure of wholesale inflation, at 8:30 a.m. EST, the Empire State Manufacturing Survey at 8:30 a.m. EST, and the Housing Market Index at 1:00 p.m. EST.

It is a big day for earnings, with BHP Billiton (NYSE: BHP), Johnson & Johnson (NYSE: