Mike Robertson walked away from Citibank last Friday to rejoin Standard Chartered in a new role as the bank's chief operating officer for Africa based in London. He leaves the regional position of e-business head for Citibank's cash management and trade after three years. The post remains vacant and, as yet, there is no indication of a replacement.

An American, Robertson has worked with Standard Chartered in London before. His move is said to be motivated by personal reasons - he has two teenage children who will be attending school in the UK. But the job is also a good one as the person in charge of operations and technology for Africa. "He has obviously been made an offer by Standard Chartered that he can't refuse. And it also happens to fit in with his personal agenda," says a former employee.

There is much speculation about who will replace Robertson in the top job at Citibank. His deputy, Anthony Nappi, has become acting e-business head until an announcement is made. One likely candidate, Piyush Gupta, a veteran of Citibank's cash management team, is out of the running following his recent elevation to Country Corporate Officer of a yet-to-be-disclosed market in South-east Asia.

Whoever takes over the reins will be required to steer the bank through some tough market conditions. The majority of cash management banks in the region are said to have fallen short of sales targets this year. And next year could prove equally difficult. "Everyone is suffering at the moment," says the former colleague. "That is why it is crucial that Citibank makes an announcement on the replacement soon. Having the position vacant for longer than a month will only send out a bad signal to the market."

Robertson's previous positions with Standard Chartered include head of product management for corporate and institutional banking, and Year 2000 programme director. In his new role he will be responsible for technology, operations, legal and compliance, corporate/external affairs and product management for Africa. He will report to Peter Sullivan and Mike Grime.