UPDATE 2-Millennium sells minority stake in Polish unit at 10 pct discount

(Corrects first bullet point to 15.41 pct from 10 pct)

* Millennium bcp sells 15.41 pct stake in Polish business

* Portuguese bank raises 304 million euros

* Shares (Berlin: DI6.BE - news) in both banks fall

By Adrian Krajewski and Andrei Khalip

WARSAW/LISBON, March 26 (Reuters) - Portugal's largest listed lender, Millennium bcp, sold a minority stake in its Polish business on Thursday at a steep 10 percent discount, raising 304 million euros ($333 million) in much needed capital.

In an accelerated placement of the 15.41 percent stake in Poland's Bank Millennium, BCP got a price of 6.65 zlotys, below Wednesday's closing price of 7.37 zlotys. It retained a controlling 50.51 percent stake in the subsidiary, which it considers core for its operations.

On the Lisbon market, shares in Millennium bcp were down 3 percent at 1400 GMT. They are however over 40 percent higher since the start of the year on expectations of a turnaround after a long period of losses

Shares in Bank Millennium, Poland's sixth largest commercial lender by assets, fell 9.6 percent on the Warsaw bourse, hitting their lowest level in 18 months. That decline reflected the discount as well as capital risks from mortgage loans denominated in Swiss francs.

BCP said the sale, designed to reinforce the bank's capital after a fall in its solvency ratio in late 2014, will increase its fully-implemented common equity Tier 1 ratio by 46 basis points. The core capital ratio fell to 8.9 percent in the fourth quarter from 10.2 percent in the third quarter.

"The price is lower than we expected, but the operation is not all that bad for BCP, it has quite a valuable impact on capital ratio," said Andre Rodrigues, a banking analyst at Caixa Banco de Investimento in Lisbon.

He added that BCP may still need more capital reinforcement measures to return to a safe 10 percent ratio.

"The market has been aggressive about capital and to address that BCP may have to take more measures, which could be a loan securitisation or sale of part of its sovereign debt portfolio."

Like several other Polish lenders, Bank Millennium has a large portfolio of mortgages denominated in Swiss francs.

These have become a potential risk after the Swiss central bank this year removed its cap on the franc, and the currency surged against the Polish zloty. That has left some borrowers struggling to make repayments.

Poland's financial regulator has warned that lenders with large foreign-exchange mortgage portfolios may have to set aside extra capital to offset risks from the loans. ($1 = 3.7027 zlotys) ($1 = 0.9060 euros) (Reporting by Anna Koper and Adrian Krajewski in Warsaw, and Andrei Khalip in Lisbon; Editing by Christian Lowe, Keith Weir and David Holmes)