Fannie Mae's mortgage portfolio grew $18.3 billion in May, to $464.8 billion, a 49.2% annual growth rate which was a sharp rise from 15.8% in April, Fannie said Thursday.
In April the portfolio grew $14.2 billion.
Fannie bought $25.6 billion of mortgages in May, the secondhighest monthly total on record.
Portfolio liquidations slipped to $7.1 billion in May from $8 billion in April. Fannie Mae said it made commitments to buy $12.3 billion of mortgages last month, down from $20.1 billion in April.
The company said its total mortgage-backed securities outstanding surged $9 billion in May to $900.8 billion, a 12.1% annual growth rate. But that was off from 13.6% in April.