• by David Goetzl  @dgoetzl, May 8, 2013

Arbitron spent more than $3 million in the first three months of this year in legal and other fees as it prepped documents for the Federal Trade Commission and answered inquiries about its pending acquisition by Nielsen.

The timing of a potential approval is unclear, a point hammered home by Nielsen CEO David Calhoun recently.

In its release of first-quarter earnings, Arbitron said it also invested $4.4 million in cross-platform initiatives and its mobile measurement unit. The amount was up from $2.9 million last year.

The FTC would be expected to review its cross-platform efforts, since Nielsen has operations in the same arena.

CEO Sean Creamer stated that the company continues to push ahead with cross-platform operations, as well as measuring digital radio and mobile usage.

Arbitron, whose core business is in radio measurement, had $111.8 million in revenue in the first quarter -- a 5.1% increase.

Net income was $16.3 million, down from $17.8 million.