Morgan Stanley CEO James Gorman said Saudi Arabia could be a "major opportunity" for the firm as the country unveiled plans for oil giant Saudi Aramco's $100 billion initial public offering and introduced a series of reforms to attract foreign capital in 2015.

Gorman, speaking at the bank's financials conference in New York, said he has personally been spending a significant amount of time in Saudi Arabia, as has President Colm Kelleher.

In May, several U.S.-based bank CEOs including Gorman, JPMorgan Chase & Co.'s Jamie Dimon and Citigroup Inc's Michael Corbat attended a business forum in Saudi Arabia.

Morgan Stanley already has a presence in Saudi Arabia, having set up an office in the region in 2007.

Other banks are scrambling to expand into the country.

Citi received a license from Saudi Arabia's regulator in April for investment banking and capital markets services, and Goldman Sachs Group Inc has applied for a license to trade equities in the kingdom.

The opening of Saudi Arabia is part of a reform agenda to diversify the Saudi economy beyond oil by 2030.

The Saudi stock exchange opened itself to direct investment from foreign entities in mid-2015 and last year loosened restrictions on foreign ownership in its stock market.