(Reuters) -Independent proxy advisory firms Glass Lewis & Co and Institutional Shareholder Services (ISS) have recommended Magellan Midstream (NYSE:MMP) Partners' unitholders to vote in favor of the pipeline operator's $18.8 billion planned sale to ONEOK (NYSE:OKE).
"We are inclined to take the view that the proposed merger would put the combined company in a better position, compared to Magellan on a standalone basis," Glass Lewis said in a statement on Wednesday.
Shares of Magellan Midstream rose 1.5% in early afternoon trading.
Energy Income Partners, the fourth-largest unitholder in Magellan with a 3.1% stake, has said it intends to vote against the proposed deal, concerned about the loss of tax benefits.
The voting on the deal is scheduled to take place on Sept. 21.
Magellan is a master limited partnership (MLP), a publicly traded corporate structure that enjoys the benefits of paying no tax at the company level.
Investors in MLPs, known as unitholders, are also shielded from ongoing taxes, but when either the units or the whole company are sold the accumulated taxes become due for payment.
"The premium also stands out among recent precedent transactions in this sector, and appears to compensate most investors for the immediate tax hit," ISS said in a report on Wednesday.