UPDATE 3-Colombia cenbank surprises with 50 bps rate cut

* Market had expected the bank to hold rate at 3.5 pct

* Rate cut prompted by low inflation expectations

* Consumer prices seen rising about 3 percent this year

(Adds analyst quote)

By Javier Mozzo

BOGOTA, April 30 (Reuters) - Colombia's central bank surprised financial markets on Friday by cutting its key interest rate by 50 basis points to 3.0 percent at its monthly rate-setting meeting, citing low inflation expectations.

Analysts had expected the bank to leave the rate unchanged at 3.5 percent, as it had for the previous four months.

"The decision was made due to the reduction in 2010 and 2011 inflation projections," central bank chief Jose Dario Uribe told reporters. "It is not because we are looking at a weaker economy. To the contrary, we are seeing an economy that is stronger."

Brazil's central bank, in contrast, raised interest rates more than expected on Wednesday, taking an aggressive stance against rising inflation, which has stoked fears Latin America's largest economy could be overheating.

Colombia's central bank sees inflation around 3 percent this year, bang in the middle of its 2 percent to 4 percent target range. A central bank poll of analysts this month predicted 3.3 percent inflation in 2011.

Earlier this year analysts feared weather disturbances associated with the El Nino phenomenon would jack up Colombian food prices. But the El Nino has been milder than expected.

Wall Street was not expecting Brazil's rate rise to be followed by a cut in Colombia.

"I think that it surprised everybody in the sense that in previous central bank communications they did not signal or indicate that they were considering rate cuts," Alberto Ramos, senior economist with Goldman Sachs.

"That does not mean the decision was wrong. I think they can perfectly well justify delivering more monetary stimulus for the economy," Ramos said.

Uribe raised the bank's view of 2010 economic growth to 3 percent from a previous outlook of 2.5 percent. Colombian gross domestic product eked out growth 0.4 percent in 2009 as the country was hit by fallout from the global financial crisis.

"I think the rationale (for the rate cut) is that expectations about economic growth are well below potential for this year. The potential is thought to be about 4.5 percent but they are expecting around 3 percent," said Bertrand Delgado, a senior economist at RGE in New York.

"The other reason is inflation has been surprising positively, meaning it has been low and expectations have been improving for the next 12 months," Delgado said.

The world slowdown had caused private investment to collapse in the last quarter of 2008. Colombia's central bank responded by chopping its key overnight rate by 6.5 percentage points over a 12-month period starting in December 2008.

On Friday, Uribe also said the central bank is indefinitely suspending sales of local TES bonds that it has purchased in the secondary market.

(Additional reporting by Daniel Bases and Walter Brandimarte in New York)

(Writing by Hugh Bronstein)