Back to work for Wall St.

NEW YORK (CNNMoney.com) -- Wall Street returns to work Wednesday morning, with investors focusing on the holiday sales results and adjusting their portfolios for the end of 2007.

Trading is expected to be light for the rest of the week, with many market participants taking an extended holiday vacation. U.S. markets were open for just a half-day on Monday, and shut all day Tuesday for Christmas.

Just after the start of trading in futures at 6 a.m. ET, S&P futures were little changed, while Nasdaq futures pointed to a higher open.

Asian stocks finished mostly higher Wednesday, with several markets still closed for holidays. Tokyo's Nikkei index gained 0.7 percent. European markets gained ground, with London closed for the Boxing Day holiday.

Retailers could get some attention when the markets open, amid indications that the holiday shopping season may have been disappointing for many of them. Target (TGT, Fortune 500) said late Monday that December same-store sales might be as weak as 1 percent lower from a year ago, and no better than 1 percent above year-earlier results.

Credit card provider MasterCard (MA) reported in its SpendingPulse report Tuesday that sales for the season - excluding gas and auto sales - increased only 2.4 percent over last year, which would put overall growth below forecasts.

The only economic report due out Wednesday is Standard & Poor's Case-Shiller index of single-family home prices, to be released just before the market opens.

Oil prices were higher. U.S. light crude rose 55 cents to $94.68 a barrel in Asian electronic trading.

The dollar was little changed against the yen.

Among stocks in the news Wednesday is Toyota Motor (TM), which announced a 2008 sales target of 9.85 million that would set an annual record if achieved. That would surpass the mark of 9.55 million set by General Motors (GM, Fortune 500) in 1978. GM, which had a slight lead on Toyota in 2007 sales through the third quarter, has yet to release its own sales target for next year.

Warren Buffett's Berkshire Hathaway (BRK.A) announced Tuesday it is paying $4.5 billion for a 60 percent stake in Marmon Holdings Inc., a privately-held conglomerate controlled by the Pritzker family in Chicago.

Late Monday after the early market close drugmaker Wyeth said it will sue generic drugmaker Teva Pharmaceutical Industries (TEVA) to recover lost profits from sales of its heartburn drug Protonix due to a version from Teva. The companies are in settlement talks, with Teva saying it has halted additional shipments of its version of the drug for 30 days. But Wyeth also suffered a setback Monday when the Food and Drug Administration demanded the drug maker answer more questions on an experimental osteoporosis medicine before it can rule on the drug.