After a two-week rally, the Los Angeles Business Journal’s index of the largest local public companies fell for the week ended Sept. 25. Disappointing economic and corporate earnings reports caused investors to worry about prospects for an economic recovery.

The weighted LABJ index closed down 2.3 percent to 107.35, with decliners outpacing gainers 112 to 66.

KB Home fell 14 percent to $16.96 after the Los Angeles home builder reported a third quarter loss that was smaller than a year ago but still failed to meet Wall Street expectations.

Ameron International Corp. dropped nearly 11 percent to $73.46 after the Pasadena steel products producer reported a steep decline in third quarter net income and received an analyst’s downgrade.

Colony Financial Inc., a Century City real estate investment trust that on Wednesday launched a $255 million initial public offering priced at $20 per share, ended the week at $19.37, down 3 percent.

Among top gainers was Los Angeles office landlord Maguire Properties Inc., which jumped nearly 74 percent to $2.43 as investors were encouraged by its efforts to sell properties and manage its debt.

Tix Corp. rose nearly 23 percent to $3.95 as the Studio City online ticketing service announced progress in getting patent protection for some of its technology.

Abraxis BioScience Inc. gained 17 percent to $34.23 after the Los Angeles biotech benefited from positive comments in an analyst’s initiation report and the company’s own presentation at a Boston investor conference.