April 2 (Reuters) - Rivian Automotive missed market estimates for quarterly production on Tuesday, impacted by the electric vehicle maker's move to transition to new suppliers for fresh materials as it looks to reduce costs and improve efficiencies.

The Amazon.com-backed company produced 13,980 vehicles in the first quarter ended March 31, while eight analysts polled by Visible Alpha had expected roughly 14,250 units.

The quarterly production figure rose around 50% year-over-year, but was below the 17,541 vehicles it produced in its preceding three months.

Rivian, the maker of R1T pickup trucks and R1S SUVs, reaffirmed its annual production forecast and is also planning a weeks-long production shut down in the second quarter to upgrade its production line.

The company reported first-quarter deliveries of 13,588, a sequential decline of around 3%, which is smaller than the 10% to 15% decline it forecast in February.

The delivery figures, which fell at a slower rate than the company's forecast, will provide some respite to investor concerns around a slowdown in EV demand as consumers look for more affordable hybrid vehicles in an uncertain economy.

Buyers in the United States have opted for hybrids over pure EVs over the past few months to avoid higher ownership costs and also as some models lost eligibility for federal tax credits.

The company said that they have produced a few thousand additional vehicles which have not been included in this quarter's figures as they await a part which they expect to receive in April.

The higher prices of battery vehicles compared to gasoline-powered cars have prompted EV makers to introduce more compact and cost effective models to draw in buyers.

Rivian unveiled its smaller, less expensive electric R2 SUVs and R3 crossovers last month and said it would produce the R2 at its existing U.S. factory, saving the company more than $2 billion. (Reporting by Zaheer Kachwala in Bengaluru; Editing by Tasim Zahid and Shailesh Kuber)