OREANDA-NEWS.  Marathon Petroleum again raised its cash offering to MarkWest unitholders ahead of the anticipated merger from $5.21 per unit to $6.20 per unit.

"Under the revised terms of the merger agreement announced today, which represents the best and final offer, MarkWest common unitholders will receive approximately $1.28bn in total cash consideration," the companies said today.

Earlier this month Marathon raised its original offer for the midstream provider after some unitholders complained the terms of the original deal were unfavorable to MarkWest investors. John Fox, co-founder and former chief executive of MarkWest, wrote a letter to the company's board 4 November protesting the merger with MPLX. Fox, who holds 1.36mn units of MarkWest, argued the original deal hurt unitholders who would see greater value with MarkWest as a standalone company. Marathon originally offered $3.37 per unit in July.

MarkWest's merger with MPLX will give Marathon access to MarkWest's liquids pipelines and processing facilities throughout the Marcellus and Utica regions. The merger is expected to close following a vote of unit holders 1 December. MarkWest's three largest investors, totaling 15pc of its outstanding units, will vote in favor of the transaction.