QUINCY, Ill. (Feb. 23)—Tire and wheel maker Titan International Inc. suffered quarterly and year-end losses due to labor and market strife. The Quincy-based company lost $5.97 million in the fourth quarter ended Dec. 31, 1999, compared to a $5.34 million loss in the same period in 1998. The firm posted net sales of $134.4 million during the quarter, down 6 percent from 1998. For the year, Titan lost $11.4 million, a significant drop from 1998, when it had profits of $8.15 million. Twelve-month sales were down 11 percent, to $588 million from $660.8 million the year before.