UPDATE 1-Williams explores building first propane dehydrogenation plant in Canada

July 19 (Reuters) - Oil and gas company Williams Companies Inc said it is considering building the first propane dehydrogenation (PDH) facility in Canada to increase its production of polymer-grade propylene from the country.

The company said it estimates spending of $600 million to $800 million for the PDH facility, and plans to fund the costs with cash on hand.

"Building a PDH facility would further build on the value and expertise that we've built in Canada and serve the booming North American petrochemical market," said David Chappell, president, Williams Energy Canada.

Williams would primarily use the propane it recovers at its Redwater facility in Alberta as feedstock for the new PDH facility.

When oil and gas producers convert the Canadian oil sands into usable oil, the process produces a rich mixture of natural gas, NGLs and olefins. In Canada, Williams' facilities extract the off-gas mixture and return the clean-burning natural gas to oil sands producer for their operations.

Then, it transports the remaining mixtures to its Redwater facility outside of Edmonton for further separation.

Separately, Williams increased its quarterly dividend to 31.25 cents per share, from 30 cents per share.

Shares of Williams Companies, which holds a more than 70 percent stake in Williams Partners, closed at $31.05 Thursday on the New York Stock Exchange.