Haimes, who was formerly managing director of Itsu, left the company he had overseen for over two years last week and it is thought that he has already got another role in the sector lined up.
Obika, which currently operates two sites in London, named Ryan Hattingh, formerly of Gaucho, as managing director for its UK subsidiary earlier this year as it looks to aggressively expand in the country. Hattingh now becomes group managing director.
Hattingh was formerly international operations director at the Argentinean steakhouse chain and took over the responsibility for an aggressive expansion plan for the brand in the UK market from Haimes.
In January, it appointed Matthew Piovan, as its new head of UK operations.
The two-strong chain will open a further site in Charlotte Street early next month, with a fourth site set to follow in Poland Street before the year end.
Obika, whose main shareholders are NEO Capital and founder Silvio Ursini, currently operates 18 restaurants in Italy, the UK, Turkey, Japan Canada and the US, and is planning further international openings this year in the UAE and Asia.
The group launched its first UK site in Canary Wharf at the end of 2011 and opened its second site in the UK in South Kensington last summer.
The Obika menu is centred on authentic buffalo mozzarella which is available with a number of accompaniments - interior design and service style differs at all the sites while takeaway is also being trialled at some of the sites.
Speaking to BigHospitality earlier this year, Haimes said private dining is now becoming a bigger part of the UK business:
"It is a very popular private dining room because there is not many in South Kensington," he explained. "Our evening trade is equally as strong as our lunchtime trade. I guess people perceive us as a mozzarella bar and perceive us to be cold food but actually our gourmet pizzas go down extremely well."