Mitsubishi UFJ Financial Group, Japan's largest bank, will issue about $11 billion in new shares to meet stricter capital requirements and boost lending in Asia, three sources familiar with the matter said.

Japanese banks have already raised $15 billion this year by issuing common shares, but have been expected to tap resurgent equity markets for more as regulators globally plan new rules requiring them to hold a thicker buffer of capital.

MUFG plans to issue the shares by the end of the year, the sources said, confirming an earlier report in the Nikkei newspaper, which pushed shares of the bank traded in the United States down nearly 8 percent.

The Group of 20 leading industrial and emerging market countries agreed in September to finalize new capital rules by the end of 2010 and set an end-2012 date for implementing tougher capital rules for banks.

Globally banks are rushing to issue common shares to bolster their Core Tier 1 ratio -- a standard of high quality capital held against risky assets. MUFG's stood at 5.8 percent in June and a 1 trillion yen share offering would boost that by about 1 percentage point, the Nikkei said.

MUFG is also keen to establish a firmer capital base so that it can boost lending to companies in fast-growing Asian economies, a key pillar of its overseas growth strategy.

This is a pre-emptive strike ahead of an international move to tighten capital requirements, said one of the sources. It will also give us a more solid capital base to compete with the big global financial institutions.

The sources spoke on condition of anonymity ahead of an official announcement, which they said could come on or around November 18, when the bank is scheduled to report its first half earnings. A MUFG spokesman declined to comment.

MUFG raised 800 billion yen in December by issuing common and preferred shares to replenish its capital after suffering from falls in the value of its equity portfolio and making a $9 billion investment in U.S. bank Morgan Stanley.

Issuing 1 trillion yen worth of stock at Friday's closing price of 508 yen would boost MUFG's number of shares outstanding by about 1.97 billion shares, or by 17 percent.

Shares of MUFG have fallen nearly 20 percent over the past 6 months, in part reflecting investor concerns it would embark on another major capital raising, especially since it is now out of the lock-up period following its last public offering.

(Editing by Alex Richardson)