Nortel Networks Makes Deal

Nortel Networks Corp. agreed to buy closely held CoreTek Inc. for up to $1.43 billion in stock to reduce the cost of making fiber-optic transmission gear. Wilmington, Mass.-based CoreTek makes lasers that can be tuned like a radio to change the color of light they generate. Tunable lasers are becoming important as Nortel and rivals seek to boost the capacity of transmission systems. Nortel rose $3.31 to close at $129.50 on the New York Stock Exchange.