U.S. petroleum distribution company Buckeye Partners has agreed to be purchased by Australian investment management company IFM Investors for $10.3 billion.

IFM Investors, via IFM Global Infrastructure Fund, is offering $41.50 per item of stock held, representing a premium of 27.5 percent to the Buckeye Partners' close of $32.55 on the last trading day prior to the agreement.

Buckeye Partners noted that the move will provide immediate and enhanced value for its unitholders with an attractive premium, that accelerates long-term returns.

The deal, subject to approval from shareholders and regulators, values Buckeye Partners, which booked revenue of $1.03 billion in the three months ended March 31, 2019, at around $6.50 billion.