The Los Angeles Business Journal’s index of the 200 largest local public companies closed up for the week ended Feb. 19, as investors were heartened by a Federal Reserve decision to start dismantling emergency lending programs to banks.

The weighted LABJ index rose more than 2 percent to 111.28, with gainers outpacing decliners 130 to 51.

Zenith National Insurance Corp. jumped more than 35 percent to $38.05 after the Woodland Hills workers compensation insurer said it was being acquired by Toronto-based Fairfax Financial Holdings Ltd. in a deal valued at $1.4 billion.

Portsmouth Square Inc. rose 19 percent to $25 after the Los Angeles real estate investment company reported a smaller fourth quarter loss.

Macerich Co. added 12 percent to $33.64 after the Santa Monica shopping mall reported a fourth-quarter loss that was better than analysts expected.

Among decliners, Trio-Tech International fell 5 percent to $3.80 after the Van Nuys semiconductor testing product company reported a larger fiscal second quarter loss than a year earlier.

Qualstar Corp., a Simi Valley data management company, also fell 5 percent to $1.99 after reporting a larger net loss in its second quarter.