Investors lauded Lennar Corp. (LEN) third-quarter results Monday, pushing the homebuilder’s stock up 8.2%, as the company reaps gains from a new unit. Miami-based Lennar returned to a profit for its fiscal third quarter, reporting earnings of $30 million, or 16 cents a share, well above analysts’ estimates. Results were bolstered by Lennar’s Rialto unit, which acquired 40% of a portfolio of distressed loans from the Federal Deposit Insurance Corp. (FDIC) earlier this year and earned $7.7 million for the quarter ending Aug. 31. The news helped Lennar’s stock price rise $1.15, or about 8.2%, to close at $15.14 Monday. But that’s still way off the $67.27 the stock was trading at back in January 2006 during the height of the housing-market bubble. Shares of both DR Horton (DHI) and Toll Brothers (TOL) climbed steadily Monday, as well. Pulte Group‘s (PHM) common stock rose 0.4% to $8.66 yesterday. Still it appears purchasing distressed assets from the federal government many only boost earnings for a short period, while homebuilders’ core operations continue to drag. Lennar reported a 15% decline in new-home orders and a 12% drop in its backlog of homes for sale for the third quarter. President and CEO Stuart Miller said the company is “optimistic that our core businesses are on the right track to achieving sustainable profitability as the housing market recovers.” “Our strategic investments in the FDIC loan portfolios and in the PPIP fund are performing extremely well and are producing strong earnings for our company,” Miller said. “Our disciplined approach to underwriting and investing in distressed opportunities holds us in good stead for future earnings growth.” Mitchell Hochberg, a principal with Madden Real Estate Ventures, said the homebuilder’s understanding of the mortgage market makes investing in distressed loans advantageous. “It makes sense for them to seek ancillary but related businesses to help raise earnings as the housing market sits on the bottom,” he said. “They’re being very clever right now. It’s a related business and one in which their executives know how to evaluate the risks.” But it’s probably not a long-term solution for earnings growth and Hochberg expects the company will review the unit’s performance in a few years and determine if it’s still self-sustainable. Write to Jason Philyaw.