NEW YORK (TheStreet) -- Energy Transfer Equity  (ETE) stock is gaining by 5.38% to $10.39 on heavy trading volume this afternoon, after it was revealed yesterday that the pipeline company might not have a tax opinion needed to complete its proposed takeover of rival Williams Cos. (WMB). 

If the deal had closed yesterday, Latham & Watkins would not have been able to deliver a a so-called "721 opinion" required for the transaction, the law firm told Energy Transfer, according to Bloomberg.

Williams Cos. disagrees with the law firm's position, and the companies are discussing the impact this could have on the closing of the deal.

"We view the current uncertainty over the opinion as yet another impediment to the ETE-WMB merger," Selman Akyol, an equity analyst at Stifel Nicolaus, told Bloomberg. "The latest transaction update from ETE muddies the waters."

Energy Transfer made a takeover offer of $43.50 for each Williams share in September. Since then, lower oil prices have deteriorated the market value of both companies by roughly half, leading investors to wonder whether the deal will close.

About 44.37 million shares of Energy Transfer have been traded so far today, well above the company's average trading volume of roughly 20.59 million shares per day. 

Separately, TheStreet Ratings team rates the stock as a "hold" with a ratings score of C.

Energy Transfer Equity's strengths such as its impressive record of earnings per share growth, compelling growth in net income and good cash flow from operations are countered by weaknesses including a generally disappointing performance in the stock itself and poor profit margins.

You can view the full analysis from the report here: ETE

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.