Tulsa-Operating margins were off for Magellan Midstream Partners LP’s ammonia pipeline business in the fourth quarter and year ending Dec. 31, 2006. Fourth-quarter margins were $300,000 on sales of $4.8 million and volumes of 189,000 st, compared to the year-ago $4.6 million, $5.9 million, and 226,000 st, respectively. Magellan said the quarter was negatively impacted by high integrity costs and an October 2006 pipeline release that reduced volumes and increased environmental costs. For the year, margins were down to $2.5 million on sales of $16.5 million and volumes of 726,000 st, versus 2005’s $7.7 million, $15.8 million, and 713,000 st. Magellan-wide, the company saw a boost in earnings for both the quarter and year. Fourth-quarter net income was $59.4 million on sales of $316.1 million, up from $37.6 million and $309.2 million, respectively. For the year, net income was $195.7 million on sales of $1.22 billion, versus 2005’s $159.5 million and $1.14 billion, respectively.