(Reuters) - Pipeline company Oneok Partners LP's (>> Oneok Partners LP) biggest shareholder Oneok Inc (>> ONEOK, Inc.) said it would buy the rest of the company for $9.3 billion, the latest master limited partnership (MLP) deal aimed at simplifying structures and increasing returns.

MLPs do not pay corporate taxes and must pay out most of their profits to investors in dividend-style distributions that attract yield-seeking investors.

But these shareholders tend to flee if a company is considering cutting or suspending dividends as was the case when the oil rout began in mid-2014, causing a slowdown in oil production and subsequently pipeline volumes.

This led to wave of consolidation among MLPs.

Sunoco Logistics Partners LP (>> Sunoco Logistics Partners L.P.) and Energy Transfer Partners (>> Energy Transfer Partners LP), both of which are controlled by general partner Energy Transfer Equity LP (>> Energy Transfer Equity LP), said in November they would combine.

In September, TransCanada Corp said its unit, Columbia Pipeline Group, offered to buy Columbia Pipeline Partners LP for about $848 million in cash.

Oneok said on Wednesday the deal would result in a dividend increase of 21 percent to 74.5 cents per share, or $2.98 annually.

Oneok's deal comes at time when U.S. pipeline companies are back in focus after U.S. President Donald Trump signed orders last month smoothing the path for the controversial Keystone XL and Dakota Access oil pipelines.

Oneok said it would pay 0.985 shares for each Oneok Partners unit it does not already own.

Based on both the stocks' closing price on Tuesday, that works out to $54.28 per share, representing a premium of 26 percent for shareholders of Oneok Partners.

Oneok Partners' units, which will not be publicly traded after the deal closes in the second quarter, were at $54.15 in premarket trade. Oneok's shares were up 1.9 percent at $56.15.

Oneok said it would issue 168.9 million shares for the deal, representing about 44.5 percent of the total outstanding shares of the combined company, on a pro forma basis.

The company will have an integrated 37,000 mile network of natural gas liquids, pipelines and processing plants in the Williston Basin, U.S. Mid-Continent, Permian Basin, Midwest and Gulf Coast.

J.P. Morgan Securities LLC is acting as Oneok's lead financial adviser and Skadden Arps, Slate, Meagher & Flom LLP will provide legal advice.

Barclays is providing financial advice to Oneok Partners Conflicts Committee and Andrews Kurth Kenyon LLP is its legal adviser.

(Reporting by Vishaka George and Swetha Gopinath in Bengaluru; Editing by Martina D'Couto)