Wall Street lower despite positive data ConAgra shares rose sharply after news that the US packaged food company bought private-label company Ralcorp for $5bn in an all-cash offer and assumed its $1.8bn of debt. The deal will create one of the biggest consumer packaged goods groups with private-label products and $18bn in annual sales. ConAgra shares jumped as high 5 per cent in pre-market trading but pared some of the gains and were 3.2 per cent higher at $29.21 by late morning. Ralcorp shares rallied 26.4 per cent to $88.76. Overall, US markets looked undecided in early morning activity, dipping in and out of positive territory in spite of positive economic data. The housing market continued to show signs of improvement with US home prices rising in September. The S&P/Case-Shiller home price index, which tracks monthly changes in the value of residential homes in 20 US cities, gained 0.4 per cent on a seasonally adjusted basis, as expected. In other economic news, US business spending rose in October by the most in five months as companies invested more in durable goods such as machinery and electronics, in spite of uncertainties about the fiscal cliff - a mix of automatic tax increases and spending cuts. "Markets are at the mercy of politicians at the moment and that is moving markets far more than fundamentals," said Liz Ann Sonder, chief investment strategist at Schwab. "We are advising our clients not to trade around fiscal cliff upsides and take a long-term view in their asset allocation," she added. An hour after the markets opened the benchmark S&P 500 index was 0.4 lower at 1,401.34. The Dow Jones Industrial Average lost 0.4 per cent to 12,917.61 while the technology-heavy Nasdaq Composite inched 0.3 per cent lower to 2,966.40. Apple shares, Nasdaq's biggest component, fell 1.3 per cent to $581.78, giving up some of the recent gains. Among notable rises was Corning , rallying 6.8 per cent to $12.12 after the US industrial manufacturer raised the fourth-quarter outlook for LCD and speciality glass sales volumes. ADT shares rose 2 per cent to $43.96 after the provider of electronic security services reported quarterly results that met Wall Street's expectations. The company also announced a $2bn share buyback programme and initiated a quarterly dividend. Positive housing numbers benefited homebuilders, with the S&P 500 subgroup adding 1.4 per cent. DR Horton rose 1.8 per cent to $19.82. PulteGroup added 1 per cent to $17.26 while Lennar Corp rose 0.7 per cent to $38.84. Dollar General shares rose 1.6 per cent to $50.09 as the discount store is set to be added to the S&P 500 index on Friday, replacing Cooper Industries, which is being acquired by Eaton Corp. Research In Motion shares dropped 6.7 per cent to $11.17 after Kantar Worldpanel, a market research company, in its latest report said the company's market share in smartphones in the US fell to 1.6 per cent. The maker of BlackBerry family of smartphones had enjoyed solid gains since September, rising more than 60 per cent, as investors were enthusiastic about the BlackBerry 10 devices due to be launched early next year.