Bill Winters, the chief executive of Standard Chartered, said the bank's capital strength is a top priority.In a letter sent to employees on Wednesday, which marked his first day in his new role, Winters insisted capital strength was a key factor for banks facing challenging economic conditions."Capital strength is a competitive advantage, especially in tough economic times," he wrote."We are reviewing all aspects of our capital strength as part of our broader business review."The FTSE 100 group has come under scrutiny for its capital strength, prompting some analysts to suggest that an equity fundraising might be necessary to boost the lender's financial strength.However, Standard Chartered has focused on building capital strength by slashing risk-weighted assets and exiting under-performing businesses.The bank has endured a turbulent time, as it was hit by two separate fines from US authorities over the last three years.In 2012, the FTSE 100 group had to pay $667m to US authorities due to failure over US sanctions against Iran, while it was fined $300m in August 2014 over the failure to comply with anti-money laundering policies.Standard Chartered shares were up 4.40% to 1,079.50p at 11:14 on Wednesday.