Indian gold premiums will average $3-$4 an ounce over London prices this year, roughly half what they were last year, because of continuing restrictions on imports that will soften demand, the head of the country’s biggest gold refiner said on Thursday. Struggling with a high trade deficit, India raised its gold import duty to a record 10 percent last year and made it mandatory to export a fifth of all bullion imports. Gold is India’s second-biggest expense on the import bill after oil.