Arbitron USA has reached a contract agreement with radio-station operator Infinity Broadcasting to provide radio ratings for that company. Infinity had previously rejected Arbitron’s ratings contract, but found that it could not sustain the business prospects of the company without standard ratings results.

In late June, Arbitron lowered its earnings and revenue targets after Infinity, a unit of Viacom Inc., said it wouldn’t renew a contract for radio ratings and other related services. The decision was expected to lower Arbitron’s 2004 revenue by $12 million.

But the new agreement, which is effective immediately, gives Infinity access to Arbitron’s quarterly radio ratings for 185 stations in 42 markets.

Taking into account the renewed contract with Infinity Broadcasting and a further review of business operations, Arbitron now expects 2004 revenue to increase 8.5% to 10.5% from 2003. The latest range suggests revenue of $296.9 million to $302.3 million for 2004.

When it looked as though Infinity wouldn’t renew, Arbitron’s earnings forecast was cut to a range of $1.53 to $1.57 a share.

Arbitron shares closed at $34.45 on Tuesday, up 81 cents, on the New York Stock Exchange.