Manila, June 16 -- The Philippine peso strengthened further against the U.S. dollar on Tuesday ahead of the expected signing of an interim peace pact between the United States and Iran on Friday, while the local stock market's main index slipped.

The local currency closed at 60.32 against the greenback, improving from 60.48 in the previous trading session.

The peso's strength was evident at the opening, when it started trading at 60.40 from Monday's 60.60. It moved between 60.29 and 60.50 during the day, bringing the day's average to 60.38.

Trading volume rose to USD2.5 billion from USD1.68 billion a day earlier.

Meanwhile, the Philippine Stock Exchange index (PSEi) declined by 0.43 percent to 6,245.75 points, while the broader All S...