Customer care and billing systems provider CSG Systems announced the results of its fourth quarter financials, citing revenue growth, but lower earnings.

For the quarter most recently ended, CSG claimed revenues of $155.2 million, a 31 percent increase from the same-year period. CSG directly cited the company's recent acquisition of Lucent Technologies' Kenan/BP billing and customer care system assets, a sale closed in February of last year, as a catalyst for the recent revenue growth.

CSG's numbers for the fourth quarter showed that the company is already reaping the benefits of that acquisition. CSG has recently signed up online marketplace eBay, Swiss mobile operator Sunrise, and the largest telecommunications group in Central Europe, Telekomunikacja Polska, for the Kenan/BP billing platform. CSG also cited expansion of relationships with AOL Time Warner, Cingular, AT&T Worldnet, BT Retail and Verizon Federal in contributing to the strong quarterly numbers.

For the entire year, CSG reported revenues of $610.9 million, up 28 percent.