Updated: 4:20 p.m. ET

Apple (AAPL) said it sold more than 1 million iPhone 3GS's last weekend, topping analysts' expectations.

About 6 million customers have downloaded the new iPhone 3.0 software over the past five days. The newest version of the iPhone was released last Wednesday.

"Customers are voting and the iPhone is winning," Apple CEO Steve Jobs said in a prepared statement.

In related news, The Wall Street Journal late Friday reported that Jobs had a liver transplant about two months ago. Jobs, who has been on medical leave since January, reportedly received the transplant at a hospital in Tennessee and is recovering well, the paper said.

Updated 2:15 p.m. ET.

A gloomy forecast from the World Bank prompted a broad sell-off in stocks today, although the market was off its worst levels.

At 2:15 p.m. ET, the Dow Jones Industrial Average ($DJIA) was down 166 points, or 2%, to 8,373 after The World Bank said the global economy will contract by 2.9% this year, a deeper contraction than the 1.7% decline the bank had forecast in March.

The Nasdaq Composite Index ($COMPX) plunged 54 points, or 3%, to 1,773, and the Standard & Poor's 500 Index ($INX) had shed 24 points, or 2.6%, to 897.

The bank also said developing countries will only grow by 1.9% this year, a big drop from the 5.9% growth seen in 2008 and the 8.1% growth in 2007.

The Dow had been down as many as 199 points at 1:20 p.m. ET. If the loss for the blue-chip index holds to the close, it would be its largest since June 15.

The loss for the S&P 500 would be its worst since May 13, and the Nasdaq was looking at its biggest decline since April 20.

Increased competition and slumping demand prompted Swiss mining giant Xstrata (XSRAY) to make an offer for rival Anglo American (AAUK) over the weekend. The bid is for a merger of equals.

A combined company would have a market value of about $68 billion, which would put it ahead of Rio Tinto (RTP) as the third-biggest mining company. BHP Billiton (BHP) is the world's biggest miner, followed by Vale (VALE), which was formerly Companhia Vale do Rio Doce and  is Brazil's largest mining company.

The housing market will be in focus this week, as investors turn to reports on existing-home and new-home sales for May.

Sales of existing homes likely rose 3% to 4% last month, to an annual pace of 4.82 to 4.85 million, the National Association of Realtors is expected to report on Tuesday. That level would be the highest since October. On Wednesday, a report on May new-home sales is also expected to show some improvement. The Commerce Department is expected to report that sales of new homes rose 2% to an annual pace of 360,000.

A two-day Federal Open Market Committee meeting begins Tuesday, and the Federal Reserve is expected to keep interest rates between zero and 0.25% in its effort to help revive the economy. The FOMC decision will be announced Wednesday afternoon.

Moviegoers said "yes" to Walt Disney's (DIS) "The Proposal" this weekend.

The romantic comedy, starring Sandra Bullock and Ryan Reynolds, took in $34.1 million and opened as the weekend's No. 1 movie. Time Warner's (TWX) "The Hangover" fell to second place, with $26.9 million in ticket sales, followed by Disney's Pixar Animation Studios "Up," which took in $21.3 million.

Nortel Networks (NRTLQ) is giving up its effort to restructure in bankruptcy court and will liquidate its assets, The Wall Street Journal reported on Sunday.

Nortel accepted a $650 milllion offer from Nokia Siemens Networks, a joint venture between Nokia (NOK) and Siemens (SMAWF), for the most lucrative part of its carrier-networks division and a wireless-research unit, the company said Friday. The offer is $200 million lower than the unsolicited bid Nokia Siemens made for pieces of Nortel's carrier-networks division back in March, however.

By Elizabeth Trotta, TheStreet.com

Premarket futures indicated a lower open for stocks in New York at the start of the new week as investors stomached increased concern for the global economy.

Premarket futures Monday for the S&P 500 lost 7.2 points to 908.5, and were 8.5 points below fair value. Futures on the Nasdaq were giving up 9 points to 1455, and were 15.1 points below fair value.

The Dow Jones Industrial Average fell 3% last week as selling interrupted the multi-week rally, and those losses looked to be extended early Monday after news that the World Bank cut its 2009 global growth forecast. It now anticipates the world economy will shrink by 2.9%, compared with the 1.9% contraction predicted in March.

The report warned that a decrease in investment in developing countries will increase poverty and unemployment, and said that while the global economy should start to grow again in late 2009, "the expected recovery is projected to be much less vigorous than normal."

In Europe, London's FTSE 100 and the Dax in Frankfurt were falling about 1.4% apiece. In Asia, the Nikkei in Japan and the Hang Seng in Hong Kong closed higher by 0.4% and 0.8%, respectively.

Updated: 11:55 p.m. ET.

Stocks ended the week lower for the first time in five weeks as declining energy shares offset gains in financial and technology shares.

The Dow Jones industrials ($INDU) were off 16 points to 8,540. The blue-chip index had been up as many as 61 points early in the day.

The Standard & Poor's 500 Index ($INX) was up 3 points to 921. And the Nasdaq Composite Index ($COMPX) was up 20 points to 1,827, with the Nasdaq-100 Index ($NDX.X) sporting a 17-point gain to 1,471.

A Federal Reserve meeting and reports on housing will affect markets in the week ahead.

For this week, the Dow was off 2.9%, with the S&P 500 off 2.7% and the Nasdaq down 1.7%. The weak market means that June is looking like a flat month. The Dow is up just 0.4%, the S&P 500 up 0.2% and the Nasdaq up 3%.

The Dow's loss this week meant that the index is now down 2.7% for the year. Only a week ago, the index finished ahead of its 2008 close of 8,776.39. The S&P 500 is still up 2% this year, with the Nasdaq up 15.9%.

• Is the market signalling a bottom is in?

Exxon Mobil (XOM) and Chevron (CVX) were the big weights on the Dow after crude oil moved lower. Bloomberg News said traders speculated that domestic supplies would rise this summer, forcing prices lower.