The long bull run for stock markets could be due a correction, according to one prominent emerging markets investor.

“There could be a substantial correction in the markets,” Mark Mobius, founding partner at Mobius Capital Partners, told CNBC’s Joumanna Bercetche Wednesday.

A 30 to 40 percent adjustment is “not unreasonable,” he said, speaking on developed as well as emerging markets. “I’m not predicting that, I’m just saying we’ve got to be ready for that,” he added. Mobius cited the long U.S. bull market, since 2009, as the reason for the correction.

“The catalyst I believe will come from continuing increases in interest rates. The (Federal Reserve) is definitely moving in that direction,” he said. “When the Fed moves, everybody else has got to move in that direction.”

Mobius also cited the potential impact of political changes on markets. “Any event could also be a trigger,” he explained.

“But most importantly we’ve seen this long bull market that needs a correction,” he said.

“Over the long term emerging markets will do very, very well,” Mobius said, but he added that “the short-term corrections can be quite dramatic.”

But early last month, Sam Stovall, chief investment strategist at the Center for Financial Research and Analysis, predicted much more modest market moves. He expected the S&P 500 to fall only 3 percent further in the present correction before hitting the bottom.

“While we could go further lower in terms of this correction, I don’t think we’re going to be falling into a new bear market,” he told CNBC.

Since a bottom hit early March 2009, the S&P has risen 289%, according to Reuters data.

Mobius was speaking to coincide with the launch of his new asset management firm Mobius Capital Partners. This will be focused on improving governance in emerging and frontier market companies.

He spoke positively about an improved working relationship with Chinese firms in particular.

“It’s been very, very gratifying to see that the Chinese government has put a lot of emphasis on corporate governance,” he said.

Mobius described a “sea change in attitude” from Chinese companies, which are becoming “much more receptive.”