Phillips 66 (PSX) said Tuesday it "strongly" disagrees with the recommendations issued by proxy advisory firms Institutional Shareholder Services and Glass Lewis.

The company said ISS and Glass Lewis failed to fully consider the impact of a potential break-up of the energy company as advocated by activist investor Elliott Investment Management.

Phillips 66 said the proxy solicitation firms largely ignored Elliott's efforts supporting a separation of the company's midstream and chemicals units. The company said its board has determined that an integrated model remains the best path forward to create shareholder value.

Phillips 66 also said it has added five new independent board members over the past four years as part of its efforts to obtain fresh perspectives and independent analysis.

Both ISS and Glass Lewis have sided with Elliott, with ISS saying in its recommendation that the activist fund's four-person board nominee slate "has the experience and independence that [Phillips 66] requires," while Glass Lewis blamed the current board lineup for an "increasingly dubious" commitment to corporate governance, according to Elliott.

The company is scheduled to elect board members at its upcoming annual meeting on May 21.

Phillips 66 shares recently were nearly 4% higher in mid-morning trade Tuesday.

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