The lira stood at 5.5750 against the dollar at 0800 GMT, firming some 0.7% from the closing price of 5.6140 on Monday, when it strengthened 1%. The currency, which was hit by a crisis last year, has risen for the last four trading days, reaching on Tuesday its strongest level since April 5.

Turkish Finance Minister Berat Albayrak is set to hold a press conference in Ankara later on Tuesday.

On Wednesday, the Fed is expected to cut rates for the first time since the depths of the financial crisis in 2008. That has had the effect of depressing the dollar and lifting emerging market currencies like the lira.

Investors are also eyeing a possible revision to Turkey's inflation outlook on Wednesday, as well as guidance on monetary policy going forward, after Turkey's central bank slashed rates last week.

Inflation has fallen from a 15-year high of over 25% last October to slightly under 16% in June.

Wednesday's inflation report will be the first by new central bank governor Murat Uysal, who took over the position after President Tayyip Erdogan sacked former governor Murat Cetinkaya some three weeks ago.

The BIST100 main share index was down 0.2% at 0803 GMT, while the banking index decline 0.28%.