(Adds details, background)
* Q3 net profit rises 4.7 pct to 450 mln riyals
* Revenue gains 27 pct to 2.7 bln riyals
* Almarai has been expanding overseas
DUBAI, Oct 8 - Saudi Arabian dairy and food producer Almarai Co posted a 4.7-percent rise in quarterly net profit on Monday but fell short of analysts' forecasts as higher commodity prices and expansion costs ate into earnings.
Saudi Arabia's biggest listed food company by market value said third-quarter earnings were 450 million riyals ($120.00 million) for the period ended Sept. 30, compared with 429.7 million riyals a year-ago.
Nine analysts forecast average profit of 469 million riyals in the quarter, according to a Reuters poll.
Revenue for the quarter rose 27 percent to 2.7 billion riyals from 2.1 billion riyals a year-ago, helped by strong performance at its bakery and poultry unit, Almarai said in a bourse statement.
"High material costs resulting from on-going erratic commodity prices, and also persistent increase in overhead costs due to the expansion in new projects" hurt profitability, Almarai said.
Almarai's board approved a $4.2-billion five-year investment plan in May to boost product innovation and develop its Saudi workforce.
Almarai has been keen to expand outside its core Gulf region. In December, the company acquired Fondomonte S.A, which owns and operates farms in Argentina, to secure feed for its dairy herd and poultry businesses.
The company also raised 1 billion riyals through its first Islamic bond in March, which it said was 4.7 times oversubscribed.
Its shares have risen 22 percent year-to-date on the Saudi bourse. The diary firm is a favourite among fund managers as it adds diversity to portfolios heavy with banking and real estate stocks. ($1 = 3.7501 Saudi riyals) (Reporting by Dinesh Nair; Editing by Amran Abocar)