Avis Budget Group's second-quarter net income fell to $15 million from $24 million

, though car rental revenue increased 5 percent on 3 percent higher rental day volume. "The impact of rising fuel costs and a weak economy began to affect commercial travel volumes in the second quarter," said CEO Ronald Nelson. Third-quarter transaction volume "continues to reflect a slowdown in the travel environment. As a result, we remain cautious in our outlook for the seasonally slower fourth quarter, for commercial travel volumes and for the pricing environment."