Tellabs, which employs 300 people at its Irish operation in Co Clare, has merged with another US telecommunications service provider, Ciena, in a $7.1 billion (£5 billion) deal. The merger was announced in New York yesterday. The enlarged entity will continue to trade as Tellabs, with the merger expected to strengthen the group's position in its sector of the telecommunications industry. Tellabs operates a complete research and development, manufacturing, marketing and service facility at Shannon, Co Clare. The Irish subsidiary is due to expand its contribution to the group's business and will formally open a new state-of-the-art 130,000 sq ft telecommunications facility in Shannon next August.