SEOUL (Reuters) - South Korea's household borrowing grew in September for a sixth straight month, but by a smaller amount than the month before, central bank data showed on Thursday.

Total household borrowing from banks stood at 1,079.8 trillion won ($806.12 billion) at the end of September, up 4.9 trillion won from end-August, according to the Bank of Korea (BOK).

The rise was smaller than the 6.9 trillion won increase in August and it also marked the first slowdown in growth since household debt started to climb in April.

Growth in mortgage loans softened as financial institutions tightened loan criteria, while other loans fell at a faster pace due to seasonal factors such as holiday bonuses, the BOK said.

($1 = 1,339.5000 won)