Phone company Windstream's quarterly report disappointed Wall Street for the third time in a row, sending its stock down to a three-year low.

The company is offering promotional prices on broadband and is seeing slower growth in sales of connections for cellular towers, forcing it to cut its earnings forecast for the fourth quarter.

Windstream's stock dropped 82 cents, or 8.7 percent, to $8.60 in midday trading. Earlier, the stock hit $8.51, the lowest level since early 2009, apart from the market-wide "flash crash" of May 6, 2010. The stock now carries an annual dividend yield of 11.6 percent of its price.

Windstream cut its annual forecast for operating earnings before interest, depreciation and amortization from a range of $2.43 billion to $2.5 billion to a range of $2.41 billion to $2.43 billion.

The Little Rock, Ark., company earned $53.7 million, or 9 cents per share, for the period ended Sept. 30. That was down from $78.1 million, or 15 cents per share, a year earlier.

Taking out costs related to acquisitions and restructuring, earnings were 12 cents per share, matching the analyst average as surveyed by FactSet.

Revenue rose 52 percent from a year ago to $1.55 billion, chiefly because Windstream bought Paetec Holding, which provides telecommunications services to business, in December for $883 million. The revenue slightly exceeded the average forecast of $1.54 billion.

The Paetec acquisition is part of a strategy to bolster Windstream's traditional phone company business, which is focused on smaller towns and rural areas, with business services.

Revenue was down 0.8 percent compared to combined Windstream and Paetec results a year ago.

Windstream has about 2.8 million phone lines, making it the ninth-largest provider of home phone service in the U.S.