ATLANTA - Delta Air Lines Inc.'s stock tumbled more than 8 percent to a new 52-week low Friday on persistent worries that the nation's third-largest carrier is headed toward bankruptcy.

Meanwhile, the airline's customer service chief said she was leaving, the latest in a string of executive departures at the financially troubled company.

Vicki Escarra, 51, said in a memo to employees Friday that she will be retiring effective Oct. 1.

Shares of Atlanta-based Delta fell 31 cents, or 8.7 percent, to close at $3.26 on the New York Stock Exchange Friday - giving the stock the biggest percentage decline in the Standard & Poor's 500 index for the session.

Ex-transport, durables rose 2.3% in August

WASHINGTON - Orders to U.S. factories for big-ticket goods dropped in August, largely weighed down by a sharp decline in demand for commercial airplanes.

The Commerce Department reported Friday that orders for durable goods - costly manufactured products expected to last at least three years - declined by 0.5 percent, following a 1.8 percent advance in July.

The manufacturing picture, however, looked better when volatile transportation equipment, such as airplanes, was excluded: Orders rose by a solid 2.3 percent in August. That compared with a flat reading for July and marked the biggest increase since March.

Toyota to expand Ala. plant's output

Toyota Motor Corp. will spend $250 million to boost an Alabama factory's output of V-8 engines, expanding the plant for the second time since it opened in 2003 as Asia's largest automaker sells more light trucks in the U.S.

The Huntsville, Ala., factory's workforce will increase by 300 jobs, or 60 percent, to 800, and annual production capacity will rise at the same rate, to 400,000 engines from 250,000.

SEC may file suit against Morningstar

Morningstar Inc., a U.S. research firm used by 3 million investors to decide what mutual funds to buy, said the Securities and Exchange Commission is investigating the company for publishing incorrect performance data for a fund.

The SEC may sue the Chicago-based firm, founded 20 years ago by Joseph Mansueto, for violating securities laws, Morningstar said in a statement. The regulator alleges that Morningstar inflated the returns of the Rock Canyon Top Flight Fund from March 12 to March 23, and took too long to correct the information.

Boone National Bank selects president-CEO

Chip Regenbogen has been named president and chief executive officer at Boone National Bank in Northern Kentucky.

The bank has assets of $32 million, deposits of $26 million and a main office in Burlington. It plans to open its first branch, in Florence, by year's end.

Trump trying again to renegotiate debt

ATLANTIC CITY, N.J. - After one deal to save his casino company fell apart this week, Donald Trump is trying a new approach.

Trump is negotiating with the bondholders to whom his Trump Hotels and Casino Resorts business owes $1.8 billion, according to published reports.

Under the deal, bondholders would trade some of the debt for a controlling interest in the company, The Star-Ledger of Newark and The Wall Street Journal reported in Friday's editions.

Neither Trump nor his spokesman returned calls Friday, nor did a spokeswoman for Chanin Capital Partners, which represents holders of Trump Casino Holdings bonds.

Wire/staff reports