The Los Angeles Business Journal’s index of largest local public companies fell for the week ended July 15 as investors worried whether Congress would act in time to raise the federal debt ceiling.

The weighted LABJ index slid 2.9 percent to 126.3, with decliners outpacing gainers 132 to 33 and 15 companies unchanged.

The largest decliner was Ixia, which dropped more than 21 percent to $10.24. The Calabasas provider of Internet and wireless network test products continued to suffer a week after the release of disappointing preliminary second quarter results that prompted analysts to downgrade shares.

Green Dot Corp. ended the week down more than 13 percent to $30.28 after two days of being one of the largest decliners on the New York Stock Exchange. The Monrovia pre-paid debit card company was affected by concerns over the U.S. debt ceiling crisis.

American Apparel Inc. gained 7.6 percent to $1.13 after the Los Angeles apparel company reported a rise in annual same-store sales.

MPG Office Trust Inc. rose 5.6 percent to $3.60 after an analyst upgraded shares when the Los Angeles real estate investment trust sold more non-core assets.