SYDNEY, May 21 (Reuters) - Australian consumer sentiment dipped in May, a survey showed on Tuesday, as renewed cost-of-living pressures and inflation concerns offset some of the relief provided by the government on energy bills and rent in the federal budget.

The Westpac-Melbourne Institute index of consumer sentiment slipped 0.3% in May, from April when it slumped 2.4%. The index reading of 82.2 showed pessimists outnumbered optimists, much as it has for months now.

"Consumer sentiment remains deeply pessimistic," Westpac senior economist Matthew Hassan said.

"While expectations improved a touch in May, this was overshadowed by a further deterioration in current conditions and fears that persistently high inflation may require further interest rate rises."

The federal budget last week included government's plans to spend billions to cut energy bills and rent, hoping to lower headline inflation and provide relief for voters grappling with higher living costs ahead of an election next year.

Sentiment among those surveyed pre-budget showed an index read of 86.8, up 5.3% compared to April but it came in at 76.6 after the budget announcement, and down 7% compared to April.

"The results suggest there was some disappointment, although a closer reading of the survey suggests this may have been more around the difficult economic context that the budget highlighted than its content," Hassan said.

Consumers were slightly more positive about the outlook for both family finances and the economy, but this was completely offset by a deterioration in current assessments of family finances and buyer sentiment, the survey showed.

The index measuring whether it was a good time to buy major household items fell 2.8%, after sliding 6.6% in April.

Despite inflation concerns, consumers were more positive on the economic outlook. That index for the year ahead rose 0.7%, while for the next five years it posted a solid 2.6% gain.

Housing-related sentiment was broadly unchanged. The time to buy a house index rose 1.6% to 76.5 in May, reversing about half of April's dip. (Reporting by Renju Jose in Sydney; Editing by Tom Hogue and Shri Navaratnam)