BUCHAREST — Romania's interim president has signed into law a rule that requires a majority of registered voters to take part in a referendum for it to be valid. Coming under pressure from the European Union, Crin Antonescu Tuesday enacted the legislation ahead of a July 29 impeachment referendum to decide the fate of suspended President Traian Basescu. The president has been impeached by parliament on grounds he overstepped his authority by meddling in government business and the judicial system. The 60-year-old former ship captain denies having committed “grave violations” of the constitution. Antonescu said he personally had doubts about the law, approved by the constitutional court last week. — AP