GREEN -- United Airlines passengers will be able to take a nonstop flight to Houston from the Akron-Canton Airport beginning in June.   The daily flight will depart at 7 a.m. and land at the Houston George Bush Intercontinental Airport at 8:50 a.m. The returning flight will leave Texas at 6:30 p.m. and arrive at Akron-Canton Airport at 10:12 p.m.   "George Bush Intercontinental Houston Airport is not only a great way to connect the region with Houston, but IAH is an exceptional gateway to Latin America and beyond," airport President and CEO Rick McQueen said in a news release. "United Airlines' new service to Houston speaks to their continued commitment to the region. We are thrilled that United is growing and adding key business destinations at the Akron-Canton Airport."   The airport does not offer a nonstop flight to Texas on any of its four airlines but does offer connecting flights to Houston, San Antonio, Dallas and Austin. United's new flight, which will begin June 8, is expected to decrease travel time to Houston by at least two hours.   United's other nonstop flights from the Akron-Canton Airport land in Chicago and in Newark, N.J.   "United has been a proud member of the Akron-Canton communities for nearly 70 years," Annette Zappala, United's director of sales, said in a news release. "This new flight between Akron-Canton and Houston will provide convenient connections for business and leisure customers traveling to the U.S. West Coast and to several destinations in Latin America."