The new branches will be opened in the next four weeks at Britam Tower in Upper Hill, Shell petrol stations on the Northern bypass, Eastern bypass road and Rhapta road.
Ms Hartley said the first branch to be opened today would be at Shell Petrol station on the Northern bypass.
The new branches will serve walk-in customers as well those working at nearby offices. The four branches will seat a maximum of 214 people.
She did not disclose the cost of their investment or the source of funding for the expansion.
The new outlets are coming at a time Kenya has seen an increase in branch expansion by local coffee chains such as Java House.
Restaurant businesses have been on expansion and capital raising plans in the race to tap Kenya’s emerging coffee drinking culture and the demand for snacks and meals.
The increased visits to coffee shops are fuelled by Kenya’s expanding middle class with higher disposable incomes to spend on luxury items.
Increased activity in this segment of the market has also coincided with the rise in the construction of new malls in Nairobi offering retailers a concentration of well-heeled shoppers.
The group also operates a central bakery, kitchen, and logistics centre that prepares and distributes artisanal baked goods, food, and drink shipments to its restaurants.