Sprint (S) on Thursday reported its financial results for the second quarter of 2012. Despite the carrier’s multi-billion dollar bet on Apple’s (AAPL) iPhone, Sprint posted another big loss in the June quarter. The nation’s No.3 carrier shed $0.46 per share, or $1.4 billion, on $7.3 billion in sales compared to an $847 million loss in the same quarter last year. Sprint sold 1.5 million iPhones, 40% of which were to new postpaid subscribers, and it added a net total of 442,000 postpaid subscribers. On the upside, postpaid churn sank to a record 1.69% and Sprint also managed its best-ever postpaid ARPU at $63.38. Despite the carrier’s poor second-quarter performance, Sprint raised its adjusted OIBDA forecast for calendar 2012 to $4.6 billion from $4.5 billion.