When it comes to financial forecasts, Barnes & Noble is hardly an open book.

That was the complaint voiced yesterday by some of the bookseller’s investors, who found it odd that B&N declined to give an annual profit forecast, even as the retailer is trying to sell itself.

B&N shares plunged $1.20, or 6 percent, yesterday to close at $18.94, after the book chain reported a steeper-than-expected fiscal fourth-quarter loss of $59.4 million. that compared to a loss of $32 million a year earlier.

“It makes no sense when you’re trying to sell the company that you would give no guidance whatsoever,” one B&N shareholder groused yesterday. “Usually in this situation, you give confident, aggressive guidance.”

The fear is that B&N Chairman Len Riggio and billionaire John Malone, the CEO of Liberty Media who made an offer valuing B&N at $17 a share, “are trying to steal the company,” the B&N shareholder added.

In addition to being hurt by liquidations at the rival Borders, B&N said red ink was spilled because of higher operating costs, including investments in the company’s fast-growing Nook e-reader device.

B&N’s results showed that profit margins stabilized despite the continued growth of lower-margin electronic books — a signal that e-book margins are recovering as volume increases, according to some analysts.

“Will you give us more information about some of the metrics to help us value the Nook opportunity over the next couple months?” Michael Prober of Clovis Capital Management asked on a conference call yesterday.

“We hear your comments and we’ll keep you apprised as we go forward,” B&N CEO William Lynch replied.