DUBAI, July 23 (Reuters) - Saudi Arabia's National Commercial Bank (NCB), the kingdom's largest lender, reported a 0.9 percent dip in second-quarter net profit on Sunday as a drop in operating expenses was offset by lower operating income.

The bank made a net profit of 2.42 billion riyals ($645.30 million) in the three months to June 30, down from 2.44 billion riyals in the same period of 2016, it said in a bourse statement.

SICO Bahrain forecast NCB would make a quarterly profit of 2.63 billion riyals.

The bank's operating income was lower due to a 121 million riyals fall in fees from banking services, as well as a 115 million riyals decline in investment-related income. Net special commission income was up 125 million riyals. Total operating expenses dropped by 220 million riyals.

Saudi companies issue brief earnings statements before publishing more detailed results later.

Banks in the kingdom are contending with sluggish economic growth as depressed oil prices prompt reduced spending by the government, companies and consumers.

Deposits at the bank, which has perhaps the closest links to the government, slipped 0.01 percent year on year to 314.69 billion riyals at the end of June, continuing the decline in levels seen in the first quarter of 2017 and 2016.

The hefty deposits Saudi banks have been able to build up in recent years have diminished more recently as the government draws down cash parked with them to help plug its budget deficit.

The bank's board of directors last month recommended a cash dividend for the first half of 2017 of 1.10 riyals per share, up from 0.60 riyals per share for the same period of last year.

Loans and advances at the end of June stood at 256.90 billion riyals, down 3 percent on a year earlier.

($1 = 3.7502 riyals)

(Reporting by Tom Arnold; Editing by Mark Potter) ((Tom.Arnold@thomsonreuters.com; +97144536265; Reuters Messaging: tom.arnold.thomsonreuters.com@reuters.net))