Chicago--Tribune Co., which publishes the Chicago Tribune and The Los Angeles Times, Friday posted a first-quarter net loss of $101.6 million due to a charge associated with new accounting rules. The loss, equivalent to 36 cents a share, compared with net income of $70.6 million, or 21 cents a share, a year earlier. The latest results included an after-tax charge of $165.6 million related to the write-down of intangible assets associated with the Tribune's acquisition of Times Mirror Co. in 2000. Meanwhile, first-quarter revenue slipped 4.6% to $1.23 billion, from $1.29 billion a year earlier. Tribune, which also owns TV stations and the Chicago Cubs baseball team, said publishing revenue fell 5.8% to $932 million. Retail advertising revenue slipped 3%, as increases from food store and home furnishings ads helped mitigate declines in department store, health care, electronics and hardware advertising.