(Reuters) - Alphabet Inc's <GOOGL.O> Google unit plans to open its ride-sharing program to Waze app users in San Francisco this fall, pitting itself against Uber Technologies Inc [UBER.UL], the Wall Street Journal reported.

Google in May launched a pilot program around its California headquarters which allowed several thousand area workers at specific firms to carpool together with users of its Wave navigation app, according to the WSJ report. (http://on.wsj.com/2bzJrcN0)

Alphabet executive David Drummond on Monday resigned from Uber's board due to increasing competition between the companies. Google in 2013 had invested $258 million in Uber, but now increasingly see each other as rivals, the WSJ reported.

Google did not respond immediately to a request for comment.

(Reporting by Aishwarya Venugopal in Bengaluru; Editing by Shounak Dasgupta)