UPDATE 1-Tata's Nano to go on sale in April, 7 mths late

* Tata says Nano to launch on March 23

* taking bookings in April

* expects delays as production disrupted by plant protests (Adds background, analyst comments)

MUMBAI, Feb 26 (Reuters) - The Nano, slated to be the world’s cheapest car at under $2,000, will finally go on sale in April after months of delay caused by problems at its main production plant.

Tata Motors TAMO.BO, India's largest vehicle maker, said on Thursday it would formally launch the Nano on March 23, and buyers could start ordering the model by the second week of April.

“The cars will be on display at Tata dealerships from the first week of April,” the company said in a statement.

The Nano, expected to be priced at around 100,000 rupees, was unveiled with great fanfare at the Delhi autoshow in January 2008, and should have gone on sale in October.

Violent protests by farmers unhappy with a compensation offer for their land had forced Tata Motors to stop work on a main plant in West Bengal state, and switch production to Gujarat state.

“We expect only limited quantities to be produced now -- maybe about 3,000 a month -- so the waiting period could be long,” said Surjit Arora, autos analyst at Prabhudas Lilladher.

Tata Motors’ new Nano plant in Gujarat, in western India, is not expected to be ready until the year-end.

The company has said it would make the first Nanos at one of its two existing plants in Pune, about 170 km north of Mumbai, and at Pantnagar in northern India.

Tata Motors, India's leading producer of trucks and third-biggest car maker, last year bought Ford Motor Co's F.N Jaguar and Land Rover brands for $2.3 billion.

The tiny Nano is expected to battle for a share in the local market for small cars that is dominated by Maruti Suzuki MRTI.BO7269.T.

“This will give tough competition to the smaller cars of Maruti, like the 800 and the Alto and high-end motorcycles,” said Arora. ($1= 50.4 rupees) (Reporting by Janaki Krishnan & Narayanan Somasundaram; Editing by Ranjit Gangadharan & Ian Geoghegan)