SANTA MONICA, Calif. — This month's new-car sales (including fleet sales) are expected to be approximately 1.171 million units, a 19.3 percent increase from April 2010 but a 6 percent decrease from March 2011, according to Edmunds.com. Retail sales are expected to be approximately 942,000 units, down from approximately 975,000 last month.

Edmunds.com analysts predict that April's seasonally adjusted annualized rate will be 13.3 million, up from 13.1 in March 2011. SAAR for retail sales will increase over last month to about 10.7 million in April.

Average automaker incentives in the U.S. are estimated to be $2,100 per vehicle sold in April 2011, down $268, or 11.3 percent, from March 2011, and down $533, or 20.2 percent, from April 2010.

“As inventories rapidly deteriorate, April could be the last month that we’ll see strong sales numbers until late summer or early fall,” said Edmunds.com Senior Analyst Jessica Caldwell. “May and June are traditionally high-volume months, and with anticipated supply constraints – especially on the fuel-efficient vehicles that have been in higher demand with spiked gas prices – inventories will be exhausted further. The big unknown is how this market will adjust to supply restrictions, when demand has been the key problem for the past three years.”

April 2011 had 27 selling days, one more than last April 2010. The chart below provides month-over-month comparisons:

The combined monthly U.S. market share for Chrysler, Ford and General Motors (GM) domestic nameplates is estimated at 45 percent in April 2011, down from 45.5 percent in April 2010 but up from 43.4 percent in March 2011.

“General Motors is poised to regain the sales crown in April after Ford briefly wrested it away in March,” said Edmunds.com Senior Analyst Michelle Krebs. “In fact, GM was the only major automaker to show a month-to-month sales increase over March, even as it — along with the rest of the industry — pulled back a bit on incentive spending.”

Edmunds.com predicts GM will sell 219,700 units in April 2011, up 19.6 percent compared to April 2010 and up 6.3 percent from March 2011. GM's market share is expected to be 18.8 percent of new vehicle sales in April 2011, up from 18.7 percent in April 2010 and up from 16.6 percent in March 2011.

Edmunds.com predicts Ford will sell 191,000 units in April 2011, up 14.0 percent compared to April 2010 but down 10.2 percent from March 2011. This would result in a new car market share of 16.3 percent of new car sales in April 2011 for Ford, down from 17.1 percent in April 2010 and down from 17.1 percent in March 2011.

Edmunds.com predicts Chrysler will sell 116,400 units in April 2011, up 21.6 percent compared to April 2010 but down 4.4 percent from March 2011. This would result in a new car market share of 9.9 percent for Chrysler in April 2011, up from 9.7 percent in April 2010 and up from 9.8 percent as in March 2011.

Edmunds.com predicts Honda will sell 129,700 units in April 2011, up 14.1 percent from April 2010 but down 3.0 percent from March 2011. Honda’s market share is expected to be 11.1 percent in April 2011, down from 11.6 percent in April 2010 but up from 10.7 percent in March 2011.

Edmunds.com predicts Nissan will sell 82,600 units in April 2011, up 29.5 percent from April 2010 but down 31.8 percent from March 2011. Nissan's market share is expected to be 7.1 percent in April 2011, up from 6.5 percent in April 2010 but down from 9.7 percent in March 2011.

Edmunds.com predicts Toyota will sell 167,400 units in April 2011, up 6.3 percent from April 2010 but down 5.0 percent from March 2011. Toyota's market share is expected to be 14.3 percent in April 2011, down from 16.0 percent in April 2010 but up from 14.1 percent in March 2011.