Pacific Investment Management Co., whose co-founder Bill Gross stunningly departed on Sept. 26, said late Friday that the Newport Beach, Calif.-firm had assets under management of $1.876 trillion as of Sept. 30, a 5 percent drop in the third quarter. Pimco had total assets under management of $1.973 trillion as of June 30, 2014 and total assets under management of $1.92 trillion as of Dec. 31, 2013.