(Adds market reaction, background on growth)
By Michael O'Boyle and Alexandra Alper
MEXICO CITY, April 30 (Reuters) - Mexico's central bank held borrowing costs steady on Thursday, pointing to persistently sluggish economic growth and noting that inflation pressures remained muted following a deep slump in the peso.
The Banco de Mexico left its key rate at 3.00 percent, as all 21 analysts surveyed by Reuters last week had expected.
Policymakers said slack in the economy would help contain price pressures. That backs analysts' expectations that they are unlikely to raise interest rates before the U.S. Federal Reserve does so, unless the peso weakens much further.
Yields on short term Mexican interest rate swaps ticked slightly lower after the statement, suggesting investors dialed back bets on the pace or timing of a Mexican rate hike.
Following signs of sluggish growth in Mexico and the United States, analysts in the Reuters' poll projected a 25-basis-point increase in the third quarter, compared with the prior poll's forecast for 50-basis-point hike.
The central bank's board projected that inflation would end the year below their 3 percent target despite the slump in the peso to a record low in March on concerns that higher U.S. rates will push investors to drop emerging market assets.
Policymakers suggested they could move to raise interest rates if the peso's losses begin to fan consumer prices higher. The board said there were no signs that higher prices from the weak currency were speeding up inflation.
The central bank said there were still risks that the economy could weaken, but that the outlook for growth had not deteriorated further from the last meeting in March.
In a poll from Banamex last week, analysts continued to cut back on their economic outlook this year, forecasting growth just above 2.8 percent in 2015 following a 2.1 percent expansion last year.
Inflation in early April cooled closer to 3 percent, giving policymakers room to leave interest rates steady to support sluggish economic growth. (With reporting by Gabriel Stargardter and Joanna Zuckerman Bernstein; Editing by Simon Gardner, Andrew Hay and Lisa Von Ahn)