UPDATE 5-Google parent's shares dive as YouTube changes, competition hurt revenue

Alphabet Inc's Google on Monday saw its slowest revenue growth in three years from increased competition in advertising, stumbles in its smartphone business and disruptive changes at YouTube that left the leading internet ad company lagging rivals.Alphabet Chief Financial Officer Ruth Porat attributed slower revenue growth to currency fluctuations, competition and unspecified product changes.The company is facing continued pressure from advertisers to tighten controls on its fast-growing YouTube