Cincinnati Bell filed papers with US trade regulators to spin off its data center colocation business CyrusOne in an initial public offering (IPO), the US telecommunications company said Wednesday.

The company said it will use proceeds from the sale partly to pay CyrusOne’s outstanding debt to its parent company. Cincinnati Bell also reported its Q2 earnings Wednesday, showing comparatively poor performance by its non-data-center business units.

Revenue from the telco’s data center business grew by US$9m or 20% year over year in the second quarter. This and Cincinnati Bell’s IT services and hardware business were the only units whose revenue grew in the quarter.

Cincinnati Bell CFO Kurt Freyberger said the company was happy with the results and would continue growing this segment of its business. The CyrusOne unit brought in $54m in revenue in Q2.

“We are extremely pleased with the 20% revenue growth of CyrusOne, and continue to believe our investment in this business and industry will provide high returns to our shareholders,” he said.

Both wireline and wireless business units’ revenue declined – the former’s by $2m and the latter’s by $8m.

Cincinnati Bell reported $368m in overall revenue for the quarter – a $5m increase from the second quarter of 2011. The company’s net income in Q2 was $5m, which translated to $0.01 earnings per share, or down $0.05 per share year over year.

The Ohio-based telco announced its plans to spin CyrusOne off in an IPO in March. Then, the company said it would offer a portion of the shares of this business for sale to the public without clarifying how big that portion would be.

Cincinnati Bell bought CyrusOne in May 2010 for $525m.