Mumbai, June 30 -- Gold futures hovered near $4,040 an ounce on Tuesday, leaving the precious metal on course for a decline of more than 12% this month and a fourth consecutive monthly loss. Sentiment remained constrained as the U.S. dollar index climbed to around 101.1, up more than 2% in June and on track for its strongest monthly performance since July last year, amid expectations that the Federal Reserve will implement additional interest rate hikes this year. Investors are now awaiting the U.S. monthly employment report for fresh guidance on the Fed's policy path, while renewed U.S.-Iran peace talks in Doha remain in focus as markets assess whether easing geopolitical tensions could further diminish gold's safe-haven appeal. Meanwhile,...