GLOBAL MARKETS-Global stocks rise on Lowe's results, dollar ebbs

* Lowe's optimism, broker views help lift Wall Street

* Dollar, yen fall as risk appetite gains big boost

* Government debt drifts lower despite Fed as stocks rally

* Oil rises 4 percent on Nigeria, U.S. refinery fire (Updates with U.S. markets activity; changes dateline, previous LONDON)

By Herbert Lash

NEW YORK, May 18 (Reuters) - Global stocks rose and the dollar weakened on Monday after results at No. 2 U.S. home improvement retailer Lowe's spurred hopes an economic recovery may be closer than previously thought and boosted risk appetite.

Rising equity markets, particularly on Wall Street, and strengthening crude oil prices fueled the view that the global downturn may be slowing.

Oil prices rose almost 4 percent as violence in top African crude exporter Nigeria and a fire at a key U.S. East Coast refinery revived supply concerns. A weaker dollar and an early equity surge also helped spur crude's gains.

Treasury debt prices eased as U.S. and European stock markets rallied sharply, denting demand for safe-haven government bonds.