Bank of America had already been dialing back its mortgage deliveries to Fannie Mae, along with declining overall production volume, before the company unexpectedly announced last week it has stopped sales to the government-sponsored enterprise altogether. But according to reports, a top Fannie official said the GSE acted first to end the relationship in frustrations with the bank’s delays in resolving repurchase issues. BofA said disputes over repurchases were one factor leading the bank to stop selling most single-family mortgages to Fannie, although the company also cited an inability to renegotiate...