Citigroup and UniCredit SpA are among the most recent banking giants to enter the country.
"The biggest boys are here now, we have competitors who are managing hundreds of times our balance sheet,'' Mr Ozince said in an interview.
According to Bloomberg, international banks spent around $17 billion on acquisitions in Turkey over the past three years.
ING Groep NV has announced the purchase of Oyak Bank for $2.7 billion, which means that Isbank is now the only major non-state bank lacking foreign investment.
Mr Ozince plans to raise $2 billion in funds mainly by the sale of real estate and stakes, although the bank's control of Sisecam is not something he plans to give up.
Lehman Brothers Holdings predicts that Isbank could advance 35 per cent in the next 12 months, outpacing competitors including Akbank TAS and Turkiye Garanti Bankasi.
Despite having to sell assets, Mr Ozince remains "seriously optimistic'' about 2008.