Twilio Inc forecast lower-than-expected revenue for the full year, and said contribution from key customer Uber Technologies Inc would drop as it cuts back on using the cloud-based communication software maker's services. Twilio's shares plunged more than 30 percent to $23.65 in after-market trading on Tuesday. Uber will reduce usage of the company's communications services over the next year, Twilio's Chief Executive Officer Jeff Lawson said on an earnings call. Uber, which used to utilize Twilio's services in the majority of its operating territories, is changing it on the basis of use case and geography, Lawson said.The ride-hailing service provider accounted for more than 10 percent of Twilio's revenue in 2016, according to a regulatory filing.Twilio forecast full-year revenue of $356 million to $362 million, below analysts' average estimate of $370.1 million. San Francisco-based Twilio's customers also include WhatsApp, which accounted for about 9 percent of the company's revenue in 2016.The company also forecast adjusted full-year loss of 27 cents-30 cents, much larger than the analysts' average estimate of a loss of 16 cents, according to Thomson Reuters I jumped 47.2 percent to $87.4 million in the first quarter, edging past analysts' estimate of $83.6 million. Net loss attributable to stockholders widened to $14.2 million from $6.5 million. On a per share basis, that translated to a loss of 16 cents, compared with a loss of 37 cents a year-earlier, due to a higher share count.Excluding items, the company reported a loss of 4 cents per share. Analysts on average had estimated a loss of 6 cents per share.Through Tuesday's close, the stock had gained about 18 percent this year.