(Reuters) - Online food order and delivery company GrubHub Inc reported a better-than-expected quarterly revenue, as more diners used its services to place orders.

The company, which has a delivery network spread across 1,100 U.S. cities as well as London, also forecast revenue of $136 million-$138 million for the current quarter, largely above analysts' average estimate of $136.2 million, according to Thomson Reuters I/B/E/S.

The number of active diners rose 19.5 percent to 7.7 million, the company said on Wednesday.

GrubHub has been fending off competition from the increasingly crowded food delivery industry from Yelp Inc, Postmates, Square Inc's Caviar, Amazon.com Inc's Prime service, Uber's [UBER.UL] UberEATS and the most recent entrant, Facebook Inc.

Net income attributable to shareholders rose to $13.2 million, or 15 cents per share, in the third quarter ended Sept. 30, from $6.9 million, or 8 cents per share, a year earlier.

Excluding items, GrubHub earned 23 cents per share. Revenue rose 44.1 percent to $123.5 million.

Analysts were expecting revenue of $118.45 on earnings of 19 cents per share.

(Reporting by Laharee Chatterjee and Narottam Medhora in Bengaluru; Editing by Shounak Dasgupta)