BP Amoco's merger with Atlantic Richfield Co (Arco) creates a $190 billion (#176 billion) oil giant which fuses companies with roots in both Persia and John D. Rockefeller's old sprawling business empire.

BP, which completed its tie-up with Amoco only in December, began life in 1901 when English adventurer William D'Arcy won a concession from the grand vizier of Persia.

D'Arcy's Anglo-Persian Oil Co struck the first Middle East oil eight years later, and went on to be involved in the first oil discoveries in Iraq in 1927 and in Kuwait in 1938. Anglo-Persian became British Petroleum in 1954.

BP had a major find in Alaska in 1969 and two years later made its first move for one of Rockefeller's old Standard Oil Trust companies when it swapped Alaskan reserves for a stake in Standard Oil of Ohio (SOhio). It bought up the rest of SOhio in 1986.

Amoco also had its roots in the Standard Oil Trust, with Rockefeller buying Lima (Ohio) oil in 1886.

In 1911 the US Supreme Court ordered the break-up of Standard Oil, leaving newly independent Standard Oil of Indiana with two operations, oil refining and domestic marketing.

Standard Oil of Indiana went on to become a big oil producer in Iran during the 1970s, but was ousted after the 1979 Islamic Revolution. It changed its name to Amoco in 1985, then bought Canada's Dome Petroleum three years later.

Meanwhile, BP continued to expand. It had a big find in the North Sea in 1970 and bought UK producer Britoil in 1987.

Following BP's first ever quarterly losses, Chairman Mr Robert Horton was axed in 1992.

Current chief executive Sir John Browne took up his post in 1995 and led last year's mega-merger with Amoco. And Sir John's latest partner, ARCO, also has historical links with Rockefeller.

ARCO started life in 1866 when Charles Lockhart and partners founded the Atlantic Petroleum Storage Company. After building a refinery in 1870, it was acquired by Rockefeller's Standard Oil Trust just four year later.

After the Standard Oil Trust was dissolved in 1911, it set about building its business, which included a system of service stations throughout the eastern part of the United States.

ARCO underwent a massive restructuring in 1985 and sold more than $3.2 billion of assets - including its entire oil refining and marketing operation east of the Rockies.

The merger of BP Amoco and ARCO creates a new company with a market capitalisation of around $190 billion, second only to Exxon/Mobil in the oil league, but above the Royal Dutch/Shell Group.