Aliso Viejo-based QLogic Corp. upped its lead over rival Emulex Corp. of Costa Mesa in first-quarter sales of a profitable piece of networking electronics.

QLogic, a maker of electronics for data storage networks, held more than 55% of host bus adapter sales in the first quarter, according to Redwood City-based market tracker Dell'Oro Group.

That was up nearly 2% from the prior quarter and 18% more than Emulex's share.

The two companies dominate the market for host bus adapters−circuit boards that link computers on data storage networks−and compete in one of the county’s oldest rivalries.

Emulex spun off QLogic in the early 1990s.

“These latest market share figures are validation that QLogic continues to gain momentum in the fibre channel adapter market by continuing to make the right technology and engineering investments and executing well with our growing customer base,” said Amit Vashi, QLogic’s vice president of marketing for its host solutions group.