Rima Qureshi, the head of Ericsson North America and a key player in Ericsson’s partnership with Cisco, is leaving the company effective today. Qureshi will join another company, but Ericsson declined to reveal her new employer.

Ericsson said that Niklas Heuveldop, currently senior vice president, chief strategy officer, and head of technology and emerging business at Ericsson will become acting head of North America. But the company also said it will be recruiting a permanent successor.

Qureshi joined Ericsson in 1993 and rose quickly through the ranks of the Swedish firm. She was in charge of the company’s code division multiple access (CDMA) unit after Ericsson purchased that business from Nortel.

But she is probably best-known for her role as chief strategy officer spearheading Ericsson’s collaboration with Cisco. The partnership between Cisco and Ericsson was announced in November 2015, and she worked closely with Hilton Romanski, Cisco’s chief strategy officer, on the deal.

Both companies have claimed the collaboration is a success. In January they said they had 200 customer engagements, and the partnership was being expanded to include more product areas.

In March, Qureshi was named head of the North America Region in addition to her role working with Cisco. This move was part of a bigger restructuring of the entire senior management team in which Ericsson whittled down the number of business units in the company.

In a statement, Ericsson President and CEO Börje Ekholm thanked Qureshi for her work at Ericsson. “Rima has been an appreciated member of our team for many years. We wish her the best in her new position,” he said.