UPDATE 1-UPM, Metsaliitto rejig Botnia venture

* UPM swaps Botnia venture stake for Uruguayan assets

* Metsaliitto-controlled M-real to get cash boost

* Shares in UPM, M-real leap

HELSINKI, July 15 (Reuters) - Finland's UPM-Kymmene (UPM1V.HE) said on Wednesday it and forestry firm Metsaliitto are to change ownership of their Botnia pulp venture, giving UPM assets in Uruguay and a cash boost to Metsaliitto's struggling M-real MRLBV.HE unit.

At 1144 GMT shares in M-real were 20 percent higher at 0.60 euros, while UPM stock was up 4.4 percent at 6.20 euros.

UPM said its stake in Botnia would drop to 17 percent from 47 percent, but it would receive Metsaliitto's and Botnia's stakes in a Uruguayan pulp mill and eucalyptus plantation. It would also get Botnia's 1.2 percent stake in Finnish energy firm PVO.

UPM said its interest bearing net debt would rise by some 400 million euros ($562 million), but the deal was expected to boost earnings next year.

M-real said in a separate statement its net debt would drop by around 550 million euros following the deal, and it would get a cash payment of some 300 million.

"M-real will use the proceeds for debt repayments. The arrangement will not have a significant impact on M-real's equity," the firm said in a statement.

Metsaliitto said separately its stake in Botnia would rise to 53 percent from 23 percent, with M-real's stake to remain steady at 30 percent.

The companies said the deal was expected to close in the last quarter of this year. (Reporting by Brett Young; Editing by Greg Mahlich)