The shares of the US investment bank jumped on the news.

Jun Ohta, the Chief Executive Officer of Sumitomo Mitsui, said that he wanted to make Jeffries an equity method affiliate that would have an interest of 20% to 50%. Ohta didn't say when his firm might make an additional investment, but indicated that such decisions would come once his company held discussions with US regulators.

Ohta said that they decided to increase their holdings. A strategic alliance was reached last year between the Japanese company and Jeffries.

A representative for the company didn't reply to a request for comment. The company is expected to report its fourth-quarter results on Monday.

It was the biggest increase since November 2008 for the stock. In the past year, the stock has increased in value.

Ohta said in an earlier interview that the two firms can do more.

He said that their investment-banking capability is attractive for them. There are possibilities in Europe. There is a weakness in our investment-banking capabilities.

The second wave of banking deals in Asia is being planned by the Japanese company.

The bank in Japan is one of many that sees the investment as attractive. The firm was one of three new bets unveiled by Warren Buffet.

There is a story about the cuts back on other banks.

The assistance was given by Sridhar Natarajan.

(Updates with previous interview starting in sixth paragraph.)