* Protests over chairman delays main business
* CEO must step down, says bank's top shareholder
* No votes taken by 1650 GMT
By Matthew Mpoke Bigg
LOME, March 3 Shareholders in pan-African lender Ecobank met on Monday to vote on proposals to reform its governance and to form a new board in the face of pressure from regulators and calls for chief executive Thierry Tanoh to resign.
Ecobank, one of the biggest banks in sub-Saharan Africa, faced criticism in January from Nigeria's securities regulator, which cited an absence of clear vision and strategy, inadequate transparency in recruiting and conflicts of interest.
Adding to the pressure, Ecobank's biggest shareholder, Public Investment Corporation (PIC) of South Africa, on Saturday called for Tanoh to resign immediately and listed grievances including failure to raise money, mismanagement and bad governance.
Tanoh, an Ivorian, took over as CEO in January 2013. He is a former vice president of the World Bank's International Finance Corporation.
As of 4:50 p.m.(1650 GMT) no votes had been taken at the closed-door meeting at the bank's headquarters in the Togolese capital Lome on the reforms or the establishment of an interim seven-member board to replace the current board of 12 people.
A protest against board chairman Andre Siaka initially prevented the meeting from considering substantive business, witnesses said.
A group of shareholders held up signs and made allegations about Siaka's business affairs in Cameroon, arguing that he should step down from his role as meeting chair.
"I have never seen anything like it," one longtime shareholder from Burkina Faso said of the protest, adding that such bank meetings were normally over by lunchtime.
Ecobank has assets of around $20 billion and operates in 33 African countries, giving it an unusually broad footprint and a significant role in financing economic expansion on a fast-growing continent.
The bank's profits rose 56 percent in the first nine months of 2013. PIC holds 18.35 percent of the bank's shares.
In February, the four members of Tanoh's Group Executive Committee, which runs the bank, called for him to step down because of what they said was a crisis of leadership. (Reporting by Matthew Mpoke Bigg; Editing by Emma Farge and Mike Collett-White)