May 18 (Reuters) - Colombian financial conglomerate Grupo Aval said on Wednesday its net profit more than doubled in the first quarter to 2.98 trillion pesos ($739 million), citing a one-time profit of 720 billion pesos after spinning off a subsidiary.

During the same three-month period last year, the company's net profit totaled 1.45 trillion pesos.

Grupo Aval's portfolio includes Colombian banks Banco de Bogota, Banco Popular, Banco AV Villas , Banco de Occidente, Corporacion Financiera Colombiana and pension fund Porvenir.

The company said interest income during January-March climbed 20.8% to 3.76 trillion pesos as its credit quality improved.

The conglomerate announced in late March it was spinning off Central American subsidiary BAC Holding International Corp (BHI), though Grupo Aval and Banco de Bogota were expected to keep 75% of direct participation in BHI.

($1 = $ 4,033.85 Colombian pesos)

(Reporting by Valentine Hilaire; Writing by Kylie Madry; Editing by David Alire Garcia and Sherry Jacob-Phillips)