It is believed FHF will consult Alcatel on consumer comms and content, with all aspects of the account led by the agency's head of consumer and EMEA brand marketing, Lauren Winter.
FHF started working on the account in January but declined to comment.
The Omnicom-owned PR agencies FleishmanHillard and Fishburn announcned plans to merge their UK operations in November 2015, following months of speculation.
The new entity has more than 200 employees and an annual fee income of £28m, according to the PRWeek Top 150.
Alcatel was established in 2004 as a joint venture between Alcatel-Lucent and Hong Kong-based telecoms provider TCL. In 2005 the venture was dissolved and Alcatel is now wholly owned by TCL, which also owns Blackberry.
Alcatel also declined to comment.
- This story originally said FHF was the EMEA creative lead for Alcatel. After this story was published, Alcatel parent company TCL confirmed it was in fact European creative lead.