Borders Group Inc. shares dropped more than 15 percent overnight on December 30 in response to reports that America’s second-largest bookseller has delayed payments to some of its vendors in order to conserve cash while struggling to refinance its debt.

Borders has been reporting losses for years, but its results worsened in recent quarters with heightened competition from Barnes & Noble and larger merchants including Amazon.com Inc., Wal-Mart Stores Inc. and Target Corp. The growing electronic book market is another challenge, although Borders has jumped into that realm, launching its e-bookstore over the summer and adding services to its website during the third quarter.

Borders is closing 16 stories. There is no assurance that any refinancing will come through. Borders has announced that it could violate terms of its debt in the first quarter of 2011 and “experience a liquidity shortfall.”

Which reminds me of Bob Shaw’s line about a company trying to market a ship that took “unplanned depth excursions.”

[Thanks to John Mansfield and David Klaus for the story.]

Update 12/31/2010: While out driving I realized I could use Google Ngram to test whether Bob made up that expression or appropriated it. The answer: a bit of both.  “Depth excursion” has been a term of art for underwater exploration since the 1960s, but Ngram returned zero hits for “unplanned depth excursion.”