UPDATE 1-Brazil produces record number of autos in April

* April output climbs to 340,900 vehicles, best month ever * Production pace slows slightly, remains above 2-yr avg * Sales, production boosted by extension of tax breaks SAO PAULO, May 7 (Reuters) - Brazil produced a record number of automobiles in April as recovering demand raised hopes that carmakers could shake off an uneven first quarter. Automobile production rose 6.8 percent and sales climbed 17.5 percent in April from March, the national automakers' association Anfavea