Borders Group Inc. Chief Financial Officer Mark Bierley is taking on the additional role of chief operating officer, the latest change to the U.S. bookseller’s upper management ranks. Bierley, who joined Borders in 1996 and became CFO last year, will oversee Borders’ information technology, supply chain management, strategic planning and other duties, the company said Friday.Earlier this month, Bennett LeBow, the bookseller’s chairman and largest shareholder, was named chief executive, while Mike Edwards became CEO of Borders Inc, its main bookselling business.

Borders also said Rosalind Thompson has been appointed senior vice president of human resources as of July 6.

Borders has contended with sharp sales declines for several quarters. Investors and analysts have faulted it for being slow to react to bookselling’s shift to digital media and falling behind rivals such as Barnes & Noble Inc and Amazon.com Inc, which have their own electronic readers and operate popular e-bookstores.

Edwards said on June 2 the company was on track to launch its own electronic bookstore this month. With only two weeks to go in June, Borders has yet to announce a date. The company is conducting internal tests and expects to debut its store soon, a spokeswoman said.

Borders shares were down 2 cents, or 1.2 percent, to $1.59 in midday trading on the New York Stock Exchange.