DUBAI  - Saudi British Bank (SABB), the kingdom's sixth-largest lender by assets, reported a 16.3 percent rise in its fourth-quarter net profit on Tuesday, missing analysts' forecasts.

The bank, an affiliate of HSBC Holdings, said it made 706 million riyals ($188 million) in the three months ending Dec. 31, compared with 607 million riyals in the same period a year earlier, according to a bourse filing.

Three analysts surveyed by Reuters had expected the bank to post an average net profit of 946.5 million riyals for the quarter.

The bank said the net profit improvement was down to an increase in operating income, driven by higher net special commission income, and a drop in operating expenses.

SABB, 40 percent owned by HSBC, and Alawwal Bank 1040.SE , 40 percent owned by Royal Bank of Scotland RBS.L , said in April that they had agreed to start merger talks, but progress has been slow.

Operating income for the quarter rose by 4.4 percent on the corresponding period of 2016 to 1.74 billion riyals, while profits from special commissions increased 5.6 percent over the same timeframe to 1.31 billion riyals.

After contending with lower state and consumer spending as a result of reduced oil prices, Saudi banks are forecast to benefit over the next year or so as rising public spending spurs credit growth.

Loans and advances at the end of December stood at 117 billion riyals, falling 3.3 percent on the same point in 2016, while deposits dipped 0.3 percent to 140.2 billion riyals.

($1 = 3.7502 riyals)

(Reporting by Katie Paul, editing by Louise Heavens)