The Los Angeles Business Journal’s index of largest local public companies closed down slightly for the week ended Nov. 19 amid mixed economic indicators.

The weighted LABJ index fell 0.57 percent to 115.44, with decliners outpacing gainers 102 to 73.

MPG Office Trust Inc., a downtown Los Angeles real estate investment trust, was the largest decliner for the week. The fall in share value was triggered by the resignation of Chief Executive Nelson Rising. Shares dropped 16 percent to $2.40.

Los Angeles homebuilder KB Home lost 13 percent to $11.24 on worries that the residential real estate recovery is slowing.

Obagi Medical Products Inc. fell 10 percent to $10.46. The Long Beach prescription skin care company announced that its two largest shareholders were selling off their stakes.

Among the biggest gainers was American Apparel Inc., which jumped 32 percent to $1.40 after Chief Executive Dov Charney increased his stake in the struggling Los Angeles apparel company to 53 percent.

Studio City entertainment ticketing company Tix Corp. gained 23 percent to $1.15 after reporting strong quarterly earnings.