By Jonathan Stempel

NEW YORK (Reuters) - Loews Corp LTR.N said on Monday fourth-quarter profit fell 31 percent, hurt by subprime investment losses and weaker-than-expected results in its insurance, tobacco and drilling businesses.

Net income at New York-based Loews, a conglomerate run by the billionaire Tisch family, fell to $512 million from $746 million a year earlier.

Profit attributable to shareholders fell to $384 million, or 72 cents per share, from $609 million, or $1.11 per share.

Excluding investments, profit was 81 cents per share, 26 cents below the average analyst forecast, according to Reuters Estimates. Revenue fell 5 percent to $4.57 billion. For all of 2007, profit was essentially unchanged at $2.49 billion.

Loews' businesses include financial, tobacco, energy and hotel companies, and as such are exposed to a broad swath of a U.S. economy that economists believe may be in recession.

"The economic outlook is very, very difficult to discern for the next quarter, or for the next year," Chief Executive James Tisch said on a conference call. "There's a lot more volatility to the economic outlook than we anticipated at any time in the recent past."

Loews shares fell to their lowest since January 2007, closing down $3.73, or 8.3 percent, at $41.

The shares at CNA Financial Corp (CNA.N: Quote, Profile, Research), a commercial insurer in which Loews owns an 89 percent stake, plunged $6.16, or 19.1 percent, to $26.07, a three-year low, hurt by the subprime losses and lower premiums as competition intensified.